diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index afc56a1..89e66de 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -2811,6 +2811,47 @@ JumbleExpr(pgssJumbleState *jstate, Node *node)
 				JumbleExpr(jstate, (Node *) conf->exclRelTlist);
 			}
 			break;
+		case T_JsonValueExpr:
+			{
+				JsonValueExpr *expr = (JsonValueExpr *) node;
+
+				JumbleExpr(jstate, (Node *) expr->expr);
+				APP_JUMB(expr->format.type);
+				APP_JUMB(expr->format.encoding);
+			}
+			break;
+		case T_JsonCtorOpts:
+			{
+				JsonCtorOpts *opts = (JsonCtorOpts *) node;
+
+				APP_JUMB(opts->returning.format.type);
+				APP_JUMB(opts->returning.format.encoding);
+				APP_JUMB(opts->returning.typid);
+				APP_JUMB(opts->returning.typmod);
+				APP_JUMB(opts->unique);
+				APP_JUMB(opts->absent_on_null);
+			}
+			break;
+		case T_JsonIsPredicateOpts:
+			{
+				JsonIsPredicateOpts *opts = (JsonIsPredicateOpts *) node;
+
+				APP_JUMB(opts->unique_keys);
+				APP_JUMB(opts->value_type);
+			}
+			break;
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+
+				APP_JUMB(jexpr->op);
+				JumbleExpr(jstate, jexpr->raw_expr);
+				JumbleExpr(jstate, jexpr->path_spec);
+				JumbleExpr(jstate, (Node *) jexpr->passing.values);
+				JumbleExpr(jstate, jexpr->on_empty.default_expr);
+				JumbleExpr(jstate, jexpr->on_error.default_expr);
+			}
+			break;
 		case T_List:
 			foreach(temp, (List *) node)
 			{
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index db5fcaf..d410e54 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -32,6 +32,7 @@
 
 #include "access/nbtree.h"
 #include "catalog/objectaccess.h"
+#include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "executor/execExpr.h"
 #include "executor/nodeSubplan.h"
@@ -44,6 +45,7 @@
 #include "pgstat.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
+#include "utils/jsonpath.h"
 #include "utils/lsyscache.h"
 #include "utils/typcache.h"
 
@@ -77,6 +79,7 @@ static void ExecBuildAggTransCall(ExprState *state, AggState *aggstate,
 					  ExprEvalStep *scratch,
 					  FunctionCallInfo fcinfo, AggStatePerTrans pertrans,
 					  int transno, int setno, int setoff, bool ishash);
+static char getJsonExprVolatility(JsonExpr *jsexpr);
 
 
 /*
@@ -2109,6 +2112,112 @@ ExecInitExprRec(Expr *node, ExprState *state,
 				break;
 			}
 
+		case T_JsonValueExpr:
+			ExecInitExprRec(((JsonValueExpr *) node)->expr, state, resv,
+							resnull);
+			break;
+
+		case T_JsonExpr:
+			{
+				JsonExpr   *jexpr = castNode(JsonExpr, node);
+				ListCell   *argexprlc;
+				ListCell   *argnamelc;
+
+				scratch.opcode = EEOP_JSONEXPR;
+				scratch.d.jsonexpr.jsexpr = jexpr;
+
+				scratch.d.jsonexpr.raw_expr =
+						palloc(sizeof(*scratch.d.jsonexpr.raw_expr));
+
+				ExecInitExprRec((Expr *) jexpr->raw_expr, state,
+								&scratch.d.jsonexpr.raw_expr->value,
+								&scratch.d.jsonexpr.raw_expr->isnull);
+
+				scratch.d.jsonexpr.pathspec =
+					palloc(sizeof(*scratch.d.jsonexpr.pathspec));
+
+				ExecInitExprRec((Expr *) jexpr->path_spec, state,
+								&scratch.d.jsonexpr.pathspec->value,
+								&scratch.d.jsonexpr.pathspec->isnull);
+
+				scratch.d.jsonexpr.formatted_expr =
+						ExecInitExpr((Expr *) jexpr->formatted_expr,
+									 state->parent);
+
+				scratch.d.jsonexpr.result_expr = jexpr->result_coercion
+					? ExecInitExpr((Expr *) jexpr->result_coercion->expr,
+								   state->parent)
+					: NULL;
+
+				scratch.d.jsonexpr.default_on_empty =
+					ExecInitExpr((Expr *) jexpr->on_empty.default_expr,
+								 state->parent);
+
+				scratch.d.jsonexpr.default_on_error =
+					ExecInitExpr((Expr *) jexpr->on_error.default_expr,
+								 state->parent);
+
+				if (jexpr->omit_quotes ||
+					(jexpr->result_coercion && jexpr->result_coercion->via_io))
+				{
+					Oid			typinput;
+
+					/* lookup the result type's input function */
+					getTypeInputInfo(jexpr->returning.typid, &typinput,
+									 &scratch.d.jsonexpr.input.typioparam);
+					fmgr_info(typinput, &scratch.d.jsonexpr.input.func);
+				}
+
+				scratch.d.jsonexpr.args = NIL;
+
+				forboth(argexprlc, jexpr->passing.values,
+						argnamelc, jexpr->passing.names)
+				{
+					Expr	   *argexpr = (Expr *) lfirst(argexprlc);
+					Value	   *argname = (Value *) lfirst(argnamelc);
+					JsonPathVariableEvalContext *var = palloc(sizeof(*var));
+
+					var->var.varName = cstring_to_text(argname->val.str);
+					var->var.typid = exprType((Node *) argexpr);
+					var->var.typmod = exprTypmod((Node *) argexpr);
+					var->var.cb = EvalJsonPathVar;
+					var->var.cb_arg = var;
+					var->estate = ExecInitExpr(argexpr, state->parent);
+					var->econtext = NULL;
+					var->evaluated = false;
+					var->value = (Datum) 0;
+					var->isnull = true;
+
+					scratch.d.jsonexpr.args =
+						lappend(scratch.d.jsonexpr.args, var);
+				}
+
+				scratch.d.jsonexpr.cache = NULL;
+
+				if (jexpr->coercions)
+				{
+					JsonCoercion **coercion;
+					struct JsonCoercionState *cstate;
+
+					for (cstate = &scratch.d.jsonexpr.coercions.null,
+						 coercion = &jexpr->coercions->null;
+						 coercion <= &jexpr->coercions->composite;
+						 coercion++, cstate++)
+					{
+						cstate->coercion = *coercion;
+						cstate->estate = *coercion ?
+							ExecInitExpr((Expr *)(*coercion)->expr,
+										 state->parent) : NULL;
+					}
+				}
+
+				if (jexpr->on_error.btype != JSON_BEHAVIOR_ERROR)
+					scratch.d.jsonexpr.volatility = getJsonExprVolatility(jexpr);
+
+				ExprEvalPushStep(state, &scratch);
+			}
+			break;
+
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
@@ -3336,3 +3445,104 @@ ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
 
 	return state;
 }
+
+static char
+getExprVolatility(Node *expr)
+{
+	if (contain_volatile_functions(expr))
+		return PROVOLATILE_VOLATILE;
+
+	if (contain_mutable_functions(expr))
+		return PROVOLATILE_STABLE;
+
+	return PROVOLATILE_IMMUTABLE;
+}
+
+static char
+getJsonCoercionVolatility(JsonCoercion *coercion, JsonReturning *returning)
+{
+	if (!coercion)
+		return PROVOLATILE_IMMUTABLE;
+
+	if (coercion->expr)
+		return getExprVolatility(coercion->expr);
+
+	if (coercion->via_io)
+	{
+		Oid			typinput;
+		Oid			typioparam;
+
+		getTypeInputInfo(returning->typid, &typinput, &typioparam);
+
+		return func_volatile(typinput);
+	}
+
+	if (coercion->via_populate)
+		return PROVOLATILE_STABLE;
+
+	return PROVOLATILE_IMMUTABLE;
+}
+
+static char
+getJsonExprVolatility(JsonExpr *jsexpr)
+{
+	char		volatility;
+	char		volatility2;
+	ListCell   *lc;
+
+	volatility = getExprVolatility(jsexpr->formatted_expr);
+
+	if (volatility == PROVOLATILE_VOLATILE)
+		return PROVOLATILE_VOLATILE;
+
+	volatility2 = getJsonCoercionVolatility(jsexpr->result_coercion,
+											&jsexpr->returning);
+
+	if (volatility2 == PROVOLATILE_VOLATILE)
+		return PROVOLATILE_VOLATILE;
+
+	if (volatility2 == PROVOLATILE_STABLE)
+		volatility = PROVOLATILE_STABLE;
+
+	if (jsexpr->coercions)
+	{
+		JsonCoercion **coercion;
+
+		for (coercion = &jsexpr->coercions->null;
+			 coercion <= &jsexpr->coercions->composite;
+			 coercion++)
+		{
+			volatility2 = getJsonCoercionVolatility(*coercion, &jsexpr->returning);
+
+			if (volatility2 == PROVOLATILE_VOLATILE)
+				return PROVOLATILE_VOLATILE;
+
+			if (volatility2 == PROVOLATILE_STABLE)
+				volatility = PROVOLATILE_STABLE;
+		}
+	}
+
+	if (jsexpr->on_empty.btype == JSON_BEHAVIOR_DEFAULT)
+	{
+		volatility2 = getExprVolatility(jsexpr->on_empty.default_expr);
+
+		if (volatility2 == PROVOLATILE_VOLATILE)
+			return PROVOLATILE_VOLATILE;
+
+		if (volatility2 == PROVOLATILE_STABLE)
+			volatility = PROVOLATILE_STABLE;
+	}
+
+	foreach(lc, jsexpr->passing.values)
+	{
+		volatility2 = getExprVolatility(lfirst(lc));
+
+		if (volatility2 == PROVOLATILE_VOLATILE)
+			return PROVOLATILE_VOLATILE;
+
+		if (volatility2 == PROVOLATILE_STABLE)
+			volatility = PROVOLATILE_STABLE;
+	}
+
+	return volatility;
+}
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 771b7e3..2d42608 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -57,6 +57,8 @@
 #include "postgres.h"
 
 #include "access/tuptoaster.h"
+#include "access/xact.h"
+#include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "commands/sequence.h"
 #include "executor/execExpr.h"
@@ -64,14 +66,20 @@
 #include "funcapi.h"
 #include "utils/memutils.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parsetree.h"
+#include "parser/parse_expr.h"
 #include "pgstat.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
+#include "utils/jsonapi.h"
+#include "utils/jsonb.h"
+#include "utils/jsonpath.h"
 #include "utils/lsyscache.h"
+#include "utils/resowner.h"
 #include "utils/timestamp.h"
 #include "utils/typcache.h"
 #include "utils/xml.h"
@@ -384,6 +392,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		&&CASE_EEOP_WINDOW_FUNC,
 		&&CASE_EEOP_SUBPLAN,
 		&&CASE_EEOP_ALTERNATIVE_SUBPLAN,
+		&&CASE_EEOP_JSONEXPR,
 		&&CASE_EEOP_AGG_STRICT_DESERIALIZE,
 		&&CASE_EEOP_AGG_DESERIALIZE,
 		&&CASE_EEOP_AGG_STRICT_INPUT_CHECK,
@@ -1781,7 +1790,13 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		{
 			/* too complex for an inline implementation */
 			ExecEvalAggOrderedTransTuple(state, op, econtext);
+			EEO_NEXT();
+		}
 
+		EEO_CASE(EEOP_JSONEXPR)
+		{
+			/* too complex for an inline implementation */
+			ExecEvalJson(state, op, econtext);
 			EEO_NEXT();
 		}
 
@@ -4103,3 +4118,460 @@ ExecEvalAggOrderedTransTuple(ExprState *state, ExprEvalStep *op,
 	ExecStoreVirtualTuple(pertrans->sortslot);
 	tuplesort_puttupleslot(pertrans->sortstates[setno], pertrans->sortslot);
 }
+
+/*
+ * Evaluate a expression substituting specified value in its CaseTestExpr nodes.
+ */
+static Datum
+ExecEvalExprPassingCaseValue(ExprState *estate, ExprContext *econtext,
+							 bool *isnull,
+							 Datum caseval_datum, bool caseval_isnull)
+{
+	Datum		res;
+	Datum		save_datum = econtext->caseValue_datum;
+	bool		save_isNull = econtext->caseValue_isNull;
+
+	econtext->caseValue_datum = caseval_datum;
+	econtext->caseValue_isNull = caseval_isnull;
+
+	PG_TRY();
+	{
+		res = ExecEvalExpr(estate, econtext, isnull);
+	}
+	PG_CATCH();
+	{
+		econtext->caseValue_datum = save_datum;
+		econtext->caseValue_isNull = save_isNull;
+
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	econtext->caseValue_datum = save_datum;
+	econtext->caseValue_isNull = save_isNull;
+
+	return res;
+}
+
+/*
+ * Evaluate a JSON error/empty behavior result.
+ */
+static Datum
+ExecEvalJsonBehavior(ExprContext *econtext, JsonBehavior *behavior,
+					 ExprState *default_estate, bool *is_null)
+{
+	*is_null = false;
+
+	switch (behavior->btype)
+	{
+		case JSON_BEHAVIOR_EMPTY_ARRAY:
+			return JsonbPGetDatum(JsonbMakeEmptyArray());
+
+		case JSON_BEHAVIOR_EMPTY_OBJECT:
+			return JsonbPGetDatum(JsonbMakeEmptyObject());
+
+		case JSON_BEHAVIOR_TRUE:
+			return BoolGetDatum(true);
+
+		case JSON_BEHAVIOR_FALSE:
+			return BoolGetDatum(false);
+
+		case JSON_BEHAVIOR_NULL:
+		case JSON_BEHAVIOR_UNKNOWN:
+			*is_null = true;
+			return (Datum) 0;
+
+		case JSON_BEHAVIOR_DEFAULT:
+			return ExecEvalExpr(default_estate, econtext, is_null);
+
+		default:
+			elog(ERROR, "unrecognized SQL/JSON behavior %d", behavior->btype);
+			return (Datum) 0;
+	}
+}
+
+/*
+ * Evaluate a coercion of a JSON item to the target type.
+ */
+static Datum
+ExecEvalJsonExprCoercion(ExprEvalStep *op, ExprContext *econtext,
+						 Datum res, bool *isNull)
+{
+	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	JsonCoercion *coercion = jexpr->result_coercion;
+	Jsonb	   *jb = *isNull ? NULL : DatumGetJsonbP(res);
+
+	if ((coercion && coercion->via_io) ||
+		(jexpr->omit_quotes && !*isNull && JB_ROOT_IS_SCALAR(jb)))
+	{
+		/* strip quotes and call typinput function */
+		char *str = *isNull ? NULL : JsonbUnquote(jb);
+
+		res = InputFunctionCall(&op->d.jsonexpr.input.func, str,
+								op->d.jsonexpr.input.typioparam,
+								jexpr->returning.typmod);
+	}
+	else if (op->d.jsonexpr.result_expr)
+		res = ExecEvalExprPassingCaseValue(op->d.jsonexpr.result_expr, econtext,
+										   isNull, res, *isNull);
+	else if (coercion && coercion->via_populate)
+		res = json_populate_type(res, JSONBOID,
+								 jexpr->returning.typid,
+								 jexpr->returning.typmod,
+								 &op->d.jsonexpr.cache,
+								 econtext->ecxt_per_query_memory,
+								 isNull);
+	/* else no coercion, simply return item */
+
+	return res;
+}
+
+/*
+ * Evaluate a JSON path variable caching computed value.
+ */
+Datum
+EvalJsonPathVar(void *cxt, bool *isnull)
+{
+	JsonPathVariableEvalContext *ecxt = cxt;
+
+	if (!ecxt->evaluated)
+	{
+		ecxt->value = ExecEvalExpr(ecxt->estate, ecxt->econtext, &ecxt->isnull);
+		ecxt->evaluated = true;
+	}
+
+	*isnull = ecxt->isnull;
+	return ecxt->value;
+}
+
+/*
+ * Prepare SQL/JSON item coercion to the output type. Returned a datum of the
+ * corresponding SQL type and a pointer to the coercion state.
+ */
+Datum
+ExecPrepareJsonItemCoercion(JsonbValue *item,
+							JsonReturning *returning,
+							struct JsonCoercionsState *coercions,
+							struct JsonCoercionState **pcoercion)
+{
+	struct JsonCoercionState *coercion;
+	Datum		res;
+	JsonbValue	jbvbuf;
+
+	if (item->type == jbvBinary && JsonContainerIsScalar(item->val.binary.data))
+		item = JsonbExtractScalar(item->val.binary.data, &jbvbuf);
+
+	/* get coercion state reference and datum of the corresponding SQL type */
+	switch (item->type)
+	{
+		case jbvNull:
+			coercion = &coercions->null;
+			res = (Datum) 0;
+			break;
+
+		case jbvString:
+			coercion = &coercions->string;
+			res = PointerGetDatum(
+				cstring_to_text_with_len(item->val.string.val,
+										 item->val.string.len));
+			break;
+
+		case jbvNumeric:
+			coercion = &coercions->numeric;
+			res = NumericGetDatum(item->val.numeric);
+			break;
+
+		case jbvBool:
+			coercion = &coercions->boolean;
+			res = BoolGetDatum(item->val.boolean);
+			break;
+
+		case jbvDatetime:
+			res = item->val.datetime.value;
+			switch (item->val.datetime.typid)
+			{
+				case DATEOID:
+					coercion = &coercions->date;
+					break;
+				case TIMEOID:
+					coercion = &coercions->time;
+					break;
+				case TIMETZOID:
+					coercion = &coercions->timetz;
+					break;
+				case TIMESTAMPOID:
+					coercion = &coercions->timestamp;
+					break;
+				case TIMESTAMPTZOID:
+					coercion = &coercions->timestamptz;
+					break;
+				default:
+					elog(ERROR, "unexpected jsonb datetime type oid %d",
+						 item->val.datetime.typid);
+					return (Datum) 0;
+			}
+			break;
+
+		case jbvArray:
+		case jbvObject:
+		case jbvBinary:
+			coercion = &coercions->composite;
+			res = JsonbPGetDatum(JsonbValueToJsonb(item));
+			break;
+
+		default:
+			elog(ERROR, "unexpected jsonb value type %d", item->type);
+			return (Datum) 0;
+	}
+
+	*pcoercion = coercion;
+
+	return res;
+}
+
+static Datum
+ExecEvalJsonExpr(ExprState *state, ExprEvalStep *op, ExprContext *econtext,
+				 JsonExpr *jexpr, JsonPath *path, Datum item, bool *resnull)
+{
+	bool		empty = false;
+	Datum		res = (Datum) 0;
+
+	if (op->d.jsonexpr.formatted_expr)
+	{
+		bool		isnull;
+
+		item = ExecEvalExprPassingCaseValue(op->d.jsonexpr.formatted_expr,
+											econtext, &isnull, item, false);
+		if (isnull)
+		{
+			/* execute domain checks for NULLs */
+			(void) ExecEvalJsonExprCoercion(op, econtext, res, resnull);
+			*resnull = true;
+			return (Datum) 0;
+		}
+	}
+
+	switch (jexpr->op)
+	{
+		case IS_JSON_QUERY:
+			res = JsonbPathQuery(item, path, jexpr->wrapper, &empty,
+								 op->d.jsonexpr.args);
+			*resnull = !DatumGetPointer(res);
+			break;
+
+		case IS_JSON_VALUE:
+			{
+				JsonbValue *jbv = JsonbPathValue(item, path, &empty,
+												 op->d.jsonexpr.args);
+				struct JsonCoercionState *jcstate;
+
+				if (!jbv)
+					break;
+
+				*resnull = false;
+
+				res = ExecPrepareJsonItemCoercion(jbv,
+										&op->d.jsonexpr.jsexpr->returning,
+										&op->d.jsonexpr.coercions,
+										&jcstate);
+
+				/* coerce item datum to the output type */
+				if ((jcstate->coercion &&
+					(jcstate->coercion->via_io ||
+					 jcstate->coercion->via_populate)) || /* ignored for scalars jsons */
+					jexpr->returning.typid == JSONOID ||
+					jexpr->returning.typid == JSONBOID)
+				{
+					/* use coercion via I/O from json[b] to the output type */
+					res = JsonbPGetDatum(JsonbValueToJsonb(jbv));
+					res = ExecEvalJsonExprCoercion(op, econtext, res, resnull);
+				}
+				else if (jcstate->estate)
+				{
+					res = ExecEvalExprPassingCaseValue(jcstate->estate,
+													   econtext,
+													   resnull,
+													   res, false);
+				}
+				/* else no coercion */
+			}
+			break;
+
+		case IS_JSON_EXISTS:
+			res = BoolGetDatum(JsonbPathExists(item, path, op->d.jsonexpr.args));
+			*resnull = false;
+			break;
+
+		default:
+			elog(ERROR, "unrecognized SQL/JSON expression op %d",
+				 jexpr->op);
+			return (Datum) 0;
+	}
+
+	if (empty)
+	{
+		if (jexpr->on_empty.btype == JSON_BEHAVIOR_ERROR)
+			ereport(ERROR,
+					(errcode(ERRCODE_NO_JSON_ITEM),
+					 errmsg("no SQL/JSON item")));
+
+		/* execute ON EMPTY behavior */
+		res = ExecEvalJsonBehavior(econtext, &jexpr->on_empty,
+								   op->d.jsonexpr.default_on_empty, resnull);
+	}
+
+	if (jexpr->op != IS_JSON_EXISTS &&
+		(!empty ? jexpr->op != IS_JSON_VALUE :
+		 /* result is already coerced in DEFAULT behavior case */
+		 jexpr->on_empty.btype != JSON_BEHAVIOR_DEFAULT))
+		res = ExecEvalJsonExprCoercion(op, econtext, res, resnull);
+
+	return res;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecEvalJson
+ * ----------------------------------------------------------------
+ */
+void
+ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
+{
+	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	Datum		item;
+	Datum		res = (Datum) 0;
+	JsonPath   *path;
+	ListCell   *lc;
+
+	*op->resnull = true;		/* until we get a result */
+	*op->resvalue = (Datum) 0;
+
+	if (op->d.jsonexpr.raw_expr->isnull || op->d.jsonexpr.pathspec->isnull)
+	{
+		/* execute domain checks for NULLs */
+		(void) ExecEvalJsonExprCoercion(op, econtext, res, op->resnull);
+
+		Assert(*op->resnull);
+		*op->resnull = true;
+
+		return;
+	}
+
+	item = op->d.jsonexpr.raw_expr->value;
+	path = DatumGetJsonPathP(op->d.jsonexpr.pathspec->value);
+
+	/* reset JSON path variable contexts */
+	foreach(lc, op->d.jsonexpr.args)
+	{
+		JsonPathVariableEvalContext *var = lfirst(lc);
+
+		var->econtext = econtext;
+		var->evaluated = false;
+	}
+
+	if (jexpr->on_error.btype == JSON_BEHAVIOR_ERROR)
+	{
+		/* No need to use PG_TRY/PG_CATCH with subtransactions. */
+		res = ExecEvalJsonExpr(state, op, econtext, jexpr, path, item,
+							   op->resnull);
+	}
+	else
+	{
+		/*
+		 * We should catch exceptions of category ERRCODE_DATA_EXCEPTION and
+		 * execute corresponding ON ERROR behavior.
+		 */
+		char		volatility = op->d.jsonexpr.volatility;
+		bool		useSubTransaction = volatility == PROVOLATILE_VOLATILE;
+		bool		useSubResourceOwner = volatility == PROVOLATILE_STABLE;
+		MemoryContext oldcontext = CurrentMemoryContext;
+		ResourceOwner oldowner = CurrentResourceOwner;
+		ResourceOwner newowner = NULL;
+		ExprContext *newecontext = econtext;
+
+		if (useSubTransaction)
+		{
+			BeginInternalSubTransaction(NULL);
+			/* Want to execute expressions inside function's memory context */
+			MemoryContextSwitchTo(oldcontext);
+			/*
+			 * We need to execute expressions with a new econtext
+			 * that belongs to the current subtransaction; if we try to use
+			 * the outer econtext then ExprContext shutdown callbacks will be
+			 * called at the wrong times.
+			 */
+			newecontext = CreateExprContext(econtext->ecxt_estate);
+		}
+		else if (useSubResourceOwner)
+		{
+			newowner = ResourceOwnerCreate(CurrentResourceOwner, "JsonExpr");
+			CurrentResourceOwner = newowner;
+		}
+
+		PG_TRY();
+		{
+			res = ExecEvalJsonExpr(state, op, newecontext, jexpr, path, item,
+								   op->resnull);
+
+			if (useSubTransaction)
+			{
+				/* Commit the inner transaction, return to outer xact context */
+				ReleaseCurrentSubTransaction();
+				MemoryContextSwitchTo(oldcontext);
+				CurrentResourceOwner = oldowner;
+				FreeExprContext(newecontext, true);
+			}
+			else if (useSubResourceOwner)
+			{
+				/* buffer pins are released here: */
+				CurrentResourceOwner = oldowner;
+				ResourceOwnerRelease(newowner,
+									 RESOURCE_RELEASE_BEFORE_LOCKS,
+									 false, true);
+				ResourceOwnerDelete(newowner);
+			}
+		}
+		PG_CATCH();
+		{
+			ErrorData  *edata;
+
+			/* Save error info in oldcontext */
+			MemoryContextSwitchTo(oldcontext);
+			edata = CopyErrorData();
+			FlushErrorState();
+
+			if (useSubTransaction)
+			{
+				/* Abort the inner transaction */
+				RollbackAndReleaseCurrentSubTransaction();
+				MemoryContextSwitchTo(oldcontext);
+				CurrentResourceOwner = oldowner;
+				FreeExprContext(newecontext, false);
+			}
+			else if (useSubResourceOwner)
+			{
+				/* buffer pins are released here: */
+				CurrentResourceOwner = oldowner;
+				ResourceOwnerRelease(newowner,
+									 RESOURCE_RELEASE_BEFORE_LOCKS,
+									 false, true);
+				ResourceOwnerDelete(newowner);
+			}
+
+			if (ERRCODE_TO_CATEGORY(edata->sqlerrcode) != ERRCODE_DATA_EXCEPTION)
+				ReThrowError(edata);
+
+			/* Execute ON ERROR behavior. */
+			res = ExecEvalJsonBehavior(econtext, &jexpr->on_error,
+									   op->d.jsonexpr.default_on_error,
+									   op->resnull);
+
+			if (jexpr->op != IS_JSON_EXISTS &&
+				/* result is already coerced in DEFAULT behavior case */
+				jexpr->on_error.btype != JSON_BEHAVIOR_DEFAULT)
+				res = ExecEvalJsonExprCoercion(op, econtext, res, op->resnull);
+		}
+		PG_END_TRY();
+	}
+
+	*op->resvalue = res;
+}
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index f215f3a..0171388 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2138,6 +2138,319 @@ _copyOnConflictExpr(const OnConflictExpr *from)
 	return newnode;
 }
 
+/*
+ * _copyJsonValueExpr
+ */
+static JsonValueExpr *
+_copyJsonValueExpr(const JsonValueExpr *from)
+{
+	JsonValueExpr  *newnode = makeNode(JsonValueExpr);
+
+	COPY_NODE_FIELD(expr);
+	COPY_SCALAR_FIELD(format);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonKeyValue
+ */
+static JsonKeyValue *
+_copyJsonKeyValue(const JsonKeyValue *from)
+{
+	JsonKeyValue *newnode = makeNode(JsonKeyValue);
+
+	COPY_NODE_FIELD(key);
+	COPY_NODE_FIELD(value);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonObjectCtor
+ */
+static JsonObjectCtor *
+_copyJsonObjectCtor(const JsonObjectCtor *from)
+{
+	JsonObjectCtor *newnode = makeNode(JsonObjectCtor);
+
+	COPY_NODE_FIELD(exprs);
+	COPY_NODE_FIELD(output);
+	COPY_SCALAR_FIELD(absent_on_null);
+	COPY_SCALAR_FIELD(unique);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonCtorOpts
+ */
+static JsonCtorOpts *
+_copyJsonCtorOpts(const JsonCtorOpts *from)
+{
+	JsonCtorOpts *newnode = makeNode(JsonCtorOpts);
+
+	COPY_SCALAR_FIELD(returning.format.type);
+	COPY_SCALAR_FIELD(returning.format.encoding);
+	COPY_LOCATION_FIELD(returning.format.location);
+	COPY_SCALAR_FIELD(returning.typid);
+	COPY_SCALAR_FIELD(returning.typmod);
+	COPY_SCALAR_FIELD(unique);
+	COPY_SCALAR_FIELD(absent_on_null);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonObjectAgg
+ */
+static JsonObjectAgg *
+_copyJsonObjectAgg(const JsonObjectAgg *from)
+{
+	JsonObjectAgg *newnode = makeNode(JsonObjectAgg);
+
+	COPY_NODE_FIELD(ctor.output);
+	COPY_NODE_FIELD(ctor.agg_filter);
+	COPY_NODE_FIELD(ctor.agg_order);
+	COPY_NODE_FIELD(ctor.over);
+	COPY_LOCATION_FIELD(ctor.location);
+	COPY_NODE_FIELD(arg);
+	COPY_SCALAR_FIELD(absent_on_null);
+	COPY_SCALAR_FIELD(unique);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonArrayCtor
+ */
+static JsonArrayCtor *
+_copyJsonArrayCtor(const JsonArrayCtor *from)
+{
+	JsonArrayCtor *newnode = makeNode(JsonArrayCtor);
+
+	COPY_NODE_FIELD(exprs);
+	COPY_NODE_FIELD(output);
+	COPY_SCALAR_FIELD(absent_on_null);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonArrayAgg
+ */
+static JsonArrayAgg *
+_copyJsonArrayAgg(const JsonArrayAgg *from)
+{
+	JsonArrayAgg *newnode = makeNode(JsonArrayAgg);
+
+	COPY_NODE_FIELD(ctor.output);
+	COPY_NODE_FIELD(ctor.agg_filter);
+	COPY_NODE_FIELD(ctor.agg_order);
+	COPY_NODE_FIELD(ctor.over);
+	COPY_LOCATION_FIELD(ctor.location);
+	COPY_NODE_FIELD(arg);
+	COPY_SCALAR_FIELD(absent_on_null);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonArrayQueryCtor
+ */
+static JsonArrayQueryCtor *
+_copyJsonArrayQueryCtor(const JsonArrayQueryCtor *from)
+{
+	JsonArrayQueryCtor *newnode = makeNode(JsonArrayQueryCtor);
+
+	COPY_NODE_FIELD(query);
+	COPY_NODE_FIELD(output);
+	COPY_SCALAR_FIELD(format);
+	COPY_SCALAR_FIELD(absent_on_null);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonExpr
+ */
+static JsonExpr *
+_copyJsonExpr(const JsonExpr *from)
+{
+	JsonExpr    *newnode = makeNode(JsonExpr);
+
+	COPY_SCALAR_FIELD(op);
+	COPY_NODE_FIELD(raw_expr);
+	COPY_NODE_FIELD(formatted_expr);
+	COPY_NODE_FIELD(result_coercion);
+	COPY_SCALAR_FIELD(format);
+	COPY_NODE_FIELD(path_spec);
+	COPY_NODE_FIELD(passing.values);
+	COPY_NODE_FIELD(passing.names);
+	COPY_SCALAR_FIELD(returning);
+	COPY_SCALAR_FIELD(on_error);
+	COPY_NODE_FIELD(on_error.default_expr);
+	COPY_SCALAR_FIELD(on_empty);
+	COPY_NODE_FIELD(on_empty.default_expr);
+	COPY_NODE_FIELD(coercions);
+	COPY_SCALAR_FIELD(wrapper);
+	COPY_SCALAR_FIELD(omit_quotes);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonCoercion
+ */
+static JsonCoercion *
+_copyJsonCoercion(const JsonCoercion *from)
+{
+	JsonCoercion *newnode = makeNode(JsonCoercion);
+
+	COPY_NODE_FIELD(expr);
+	COPY_SCALAR_FIELD(via_populate);
+	COPY_SCALAR_FIELD(via_io);
+	COPY_SCALAR_FIELD(collation);
+
+	return newnode;
+}
+
+/*
+ * _copylJsonItemCoercions
+ */
+static JsonItemCoercions *
+_copyJsonItemCoercions(const JsonItemCoercions *from)
+{
+	JsonItemCoercions *newnode = makeNode(JsonItemCoercions);
+
+	COPY_NODE_FIELD(null);
+	COPY_NODE_FIELD(string);
+	COPY_NODE_FIELD(numeric);
+	COPY_NODE_FIELD(boolean);
+	COPY_NODE_FIELD(date);
+	COPY_NODE_FIELD(time);
+	COPY_NODE_FIELD(timetz);
+	COPY_NODE_FIELD(timestamp);
+	COPY_NODE_FIELD(timestamptz);
+	COPY_NODE_FIELD(composite);
+
+	return newnode;
+}
+
+
+/*
+ * _copyJsonFuncExpr
+ */
+static JsonFuncExpr *
+_copyJsonFuncExpr(const JsonFuncExpr *from)
+{
+	JsonFuncExpr   *newnode = makeNode(JsonFuncExpr);
+
+	COPY_SCALAR_FIELD(op);
+	COPY_NODE_FIELD(common);
+	COPY_NODE_FIELD(output);
+	COPY_NODE_FIELD(on_empty);
+	COPY_NODE_FIELD(on_error);
+	COPY_SCALAR_FIELD(wrapper);
+	COPY_SCALAR_FIELD(omit_quotes);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonIsPredicate
+ */
+static JsonIsPredicate *
+_copyJsonIsPredicate(const JsonIsPredicate *from)
+{
+	JsonIsPredicate *newnode = makeNode(JsonIsPredicate);
+
+	COPY_NODE_FIELD(expr);
+	COPY_SCALAR_FIELD(format);
+	COPY_SCALAR_FIELD(vtype);
+	COPY_SCALAR_FIELD(unique_keys);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonIsPredicateOpts
+ */
+static JsonIsPredicateOpts *
+_copyJsonIsPredicateOpts(const JsonIsPredicateOpts *from)
+{
+	JsonIsPredicateOpts *newnode = makeNode(JsonIsPredicateOpts);
+
+	COPY_SCALAR_FIELD(value_type);
+	COPY_SCALAR_FIELD(unique_keys);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonBehavior
+ */
+static JsonBehavior *
+_copyJsonBehavior(const JsonBehavior *from)
+{
+	JsonBehavior   *newnode = makeNode(JsonBehavior);
+
+	COPY_SCALAR_FIELD(btype);
+	COPY_NODE_FIELD(default_expr);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonOutput
+ */
+static JsonOutput *
+_copyJsonOutput(const JsonOutput *from)
+{
+	JsonOutput	   *newnode = makeNode(JsonOutput);
+
+	COPY_NODE_FIELD(typename);
+	COPY_SCALAR_FIELD(returning);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonCommon
+ */
+static JsonCommon *
+_copyJsonCommon(const JsonCommon *from)
+{
+	JsonCommon	   *newnode = makeNode(JsonCommon);
+
+	COPY_NODE_FIELD(expr);
+	COPY_NODE_FIELD(pathspec);
+	COPY_STRING_FIELD(pathname);
+	COPY_NODE_FIELD(passing);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonArgument
+ */
+static JsonArgument *
+_copyJsonArgument(const JsonArgument *from)
+{
+	JsonArgument   *newnode = makeNode(JsonArgument);
+
+	COPY_NODE_FIELD(val);
+	COPY_STRING_FIELD(name);
+
+	return newnode;
+}
+
 /* ****************************************************************
  *						relation.h copy functions
  *
@@ -5028,6 +5341,60 @@ copyObjectImpl(const void *from)
 		case T_OnConflictExpr:
 			retval = _copyOnConflictExpr(from);
 			break;
+		case T_JsonValueExpr:
+			retval = _copyJsonValueExpr(from);
+			break;
+		case T_JsonKeyValue:
+			retval = _copyJsonKeyValue(from);
+			break;
+		case T_JsonCtorOpts:
+			retval = _copyJsonCtorOpts(from);
+			break;
+		case T_JsonObjectCtor:
+			retval = _copyJsonObjectCtor(from);
+			break;
+		case T_JsonObjectAgg:
+			retval = _copyJsonObjectAgg(from);
+			break;
+		case T_JsonArrayCtor:
+			retval = _copyJsonArrayCtor(from);
+			break;
+		case T_JsonArrayQueryCtor:
+			retval = _copyJsonArrayQueryCtor(from);
+			break;
+		case T_JsonArrayAgg:
+			retval = _copyJsonArrayAgg(from);
+			break;
+		case T_JsonIsPredicate:
+			retval = _copyJsonIsPredicate(from);
+			break;
+		case T_JsonIsPredicateOpts:
+			retval = _copyJsonIsPredicateOpts(from);
+			break;
+		case T_JsonFuncExpr:
+			retval = _copyJsonFuncExpr(from);
+			break;
+		case T_JsonExpr:
+			retval = _copyJsonExpr(from);
+			break;
+		case T_JsonCommon:
+			retval = _copyJsonCommon(from);
+			break;
+		case T_JsonOutput:
+			retval = _copyJsonOutput(from);
+			break;
+		case T_JsonBehavior:
+			retval = _copyJsonBehavior(from);
+			break;
+		case T_JsonArgument:
+			retval = _copyJsonArgument(from);
+			break;
+		case T_JsonCoercion:
+			retval = _copyJsonCoercion(from);
+			break;
+		case T_JsonItemCoercions:
+			retval = _copyJsonItemCoercions(from);
+			break;
 
 			/*
 			 * RELATION NODES
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 7c28151..c0ce2d2 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -818,6 +818,108 @@ _equalOnConflictExpr(const OnConflictExpr *a, const OnConflictExpr *b)
 	return true;
 }
 
+static bool
+_equalJsonValueExpr(const JsonValueExpr *a, const JsonValueExpr *b)
+{
+	COMPARE_NODE_FIELD(expr);
+	COMPARE_SCALAR_FIELD(format.type);
+	COMPARE_SCALAR_FIELD(format.encoding);
+	COMPARE_LOCATION_FIELD(format.location);
+
+	return true;
+}
+
+static bool
+_equalJsonCtorOpts(const JsonCtorOpts *a, const JsonCtorOpts *b)
+{
+	COMPARE_SCALAR_FIELD(returning.format.type);
+	COMPARE_SCALAR_FIELD(returning.format.encoding);
+	COMPARE_LOCATION_FIELD(returning.format.location);
+	COMPARE_SCALAR_FIELD(returning.typid);
+	COMPARE_SCALAR_FIELD(returning.typmod);
+	COMPARE_SCALAR_FIELD(absent_on_null);
+	COMPARE_SCALAR_FIELD(unique);
+
+	return true;
+}
+
+static bool
+_equalJsonIsPredicateOpts(const JsonIsPredicateOpts *a,
+						  const JsonIsPredicateOpts *b)
+{
+	COMPARE_SCALAR_FIELD(value_type);
+	COMPARE_SCALAR_FIELD(unique_keys);
+
+	return true;
+}
+
+/*
+ * _equalJsonExpr
+ */
+static bool
+_equalJsonExpr(const JsonExpr *a, const JsonExpr *b)
+{
+	COMPARE_SCALAR_FIELD(op);
+	COMPARE_NODE_FIELD(raw_expr);
+	COMPARE_NODE_FIELD(formatted_expr);
+	COMPARE_NODE_FIELD(result_coercion);
+	COMPARE_SCALAR_FIELD(format.type);
+	COMPARE_SCALAR_FIELD(format.encoding);
+	COMPARE_LOCATION_FIELD(format.location);
+	COMPARE_NODE_FIELD(path_spec);
+	COMPARE_NODE_FIELD(passing.values);
+	COMPARE_NODE_FIELD(passing.names);
+	COMPARE_SCALAR_FIELD(returning.format.type);
+	COMPARE_SCALAR_FIELD(returning.format.encoding);
+	COMPARE_LOCATION_FIELD(returning.format.location);
+	COMPARE_SCALAR_FIELD(returning.typid);
+	COMPARE_SCALAR_FIELD(returning.typmod);
+	COMPARE_SCALAR_FIELD(on_error.btype);
+	COMPARE_NODE_FIELD(on_error.default_expr);
+	COMPARE_SCALAR_FIELD(on_empty.btype);
+	COMPARE_NODE_FIELD(on_empty.default_expr);
+	COMPARE_NODE_FIELD(coercions);
+	COMPARE_SCALAR_FIELD(wrapper);
+	COMPARE_SCALAR_FIELD(omit_quotes);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
+/*
+ * _equalJsonCoercion
+ */
+static bool
+_equalJsonCoercion(const JsonCoercion *a, const JsonCoercion *b)
+{
+	COMPARE_NODE_FIELD(expr);
+	COMPARE_SCALAR_FIELD(via_populate);
+	COMPARE_SCALAR_FIELD(via_io);
+	COMPARE_SCALAR_FIELD(collation);
+
+	return true;
+}
+
+/*
+ * _equalJsonItemCoercions
+ */
+static bool
+_equalJsonItemCoercions(const JsonItemCoercions *a, const JsonItemCoercions *b)
+{
+	COMPARE_NODE_FIELD(null);
+	COMPARE_NODE_FIELD(string);
+	COMPARE_NODE_FIELD(numeric);
+	COMPARE_NODE_FIELD(boolean);
+	COMPARE_NODE_FIELD(date);
+	COMPARE_NODE_FIELD(time);
+	COMPARE_NODE_FIELD(timetz);
+	COMPARE_NODE_FIELD(timestamp);
+	COMPARE_NODE_FIELD(timestamptz);
+	COMPARE_NODE_FIELD(composite);
+
+	return true;
+}
+
 /*
  * Stuff from relation.h
  */
@@ -3173,6 +3275,24 @@ equal(const void *a, const void *b)
 		case T_JoinExpr:
 			retval = _equalJoinExpr(a, b);
 			break;
+		case T_JsonValueExpr:
+			retval = _equalJsonValueExpr(a, b);
+			break;
+		case T_JsonCtorOpts:
+			retval = _equalJsonCtorOpts(a, b);
+			break;
+		case T_JsonIsPredicateOpts:
+			retval = _equalJsonIsPredicateOpts(a, b);
+			break;
+		case T_JsonExpr:
+			retval = _equalJsonExpr(a, b);
+			break;
+		case T_JsonCoercion:
+			retval = _equalJsonCoercion(a, b);
+			break;
+		case T_JsonItemCoercions:
+			retval = _equalJsonItemCoercions(a, b);
+			break;
 
 			/*
 			 * RELATION NODES
diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c
index 1bd2599..ebc41ea 100644
--- a/src/backend/nodes/makefuncs.c
+++ b/src/backend/nodes/makefuncs.c
@@ -20,6 +20,7 @@
 #include "fmgr.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
+#include "utils/errcodes.h"
 #include "utils/lsyscache.h"
 
 
@@ -628,3 +629,87 @@ makeVacuumRelation(RangeVar *relation, Oid oid, List *va_cols)
 	v->va_cols = va_cols;
 	return v;
 }
+
+/*
+ * makeJsonValueExpr -
+ *	  creates a JsonValueExpr node
+ */
+JsonValueExpr *
+makeJsonValueExpr(Expr *expr, JsonFormat format)
+{
+	JsonValueExpr *jve = makeNode(JsonValueExpr);
+
+	jve->expr = expr;
+	jve->format = format;
+
+	return jve;
+}
+
+/*
+ * makeJsonBehavior -
+ *	  creates a JsonBehavior node
+ */
+JsonBehavior *
+makeJsonBehavior(JsonBehaviorType type, Node *default_expr)
+{
+	JsonBehavior *behavior = makeNode(JsonBehavior);
+
+	behavior->btype = type;
+	behavior->default_expr = default_expr;
+
+	return behavior;
+}
+
+/*
+ * makeJsonEncoding -
+ *	  converts JSON encoding name to enum JsonEncoding
+ */
+JsonEncoding
+makeJsonEncoding(char *name)
+{
+	if (!pg_strcasecmp(name, "utf8"))
+		return JS_ENC_UTF8;
+	if (!pg_strcasecmp(name, "utf16"))
+		return JS_ENC_UTF16;
+	if (!pg_strcasecmp(name, "utf32"))
+		return JS_ENC_UTF32;
+
+	ereport(ERROR,
+			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+			 errmsg("unrecognized JSON encoding: %s", name)));
+
+	return JS_ENC_DEFAULT;
+}
+
+/*
+ * makeJsonKeyValue -
+ *	  creates a JsonKeyValue node
+ */
+Node *
+makeJsonKeyValue(Node *key, Node *value)
+{
+	JsonKeyValue *n = makeNode(JsonKeyValue);
+
+	n->key = (Expr *) key;
+	n->value = castNode(JsonValueExpr, value);
+
+	return (Node *) n;
+}
+
+/*
+ * makeJsonIsPredicate -
+ *	  creates a JsonIsPredicate node
+ */
+Node *
+makeJsonIsPredicate(Node *expr, JsonFormat format, JsonValueType vtype,
+					bool unique_keys)
+{
+	JsonIsPredicate *n = makeNode(JsonIsPredicate);
+
+	n->expr = expr;
+	n->format = format;
+	n->vtype = vtype;
+	n->unique_keys = unique_keys;
+
+	return (Node *) n;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 6c76c41..79cb602 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -259,6 +259,15 @@ exprType(const Node *expr)
 		case T_PlaceHolderVar:
 			type = exprType((Node *) ((const PlaceHolderVar *) expr)->phexpr);
 			break;
+		case T_JsonValueExpr:
+			type = exprType((Node *) ((const JsonValueExpr *) expr)->expr);
+			break;
+		case T_JsonExpr:
+			type = ((const JsonExpr *) expr)->returning.typid;
+			break;
+		case T_JsonCoercion:
+			type = exprType(((const JsonCoercion *) expr)->expr);
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			type = InvalidOid;	/* keep compiler quiet */
@@ -492,6 +501,12 @@ exprTypmod(const Node *expr)
 			return ((const SetToDefault *) expr)->typeMod;
 		case T_PlaceHolderVar:
 			return exprTypmod((Node *) ((const PlaceHolderVar *) expr)->phexpr);
+		case T_JsonValueExpr:
+			return exprTypmod((Node *) ((const JsonValueExpr *) expr)->expr);
+		case T_JsonExpr:
+			return ((JsonExpr *) expr)->returning.typmod;
+		case T_JsonCoercion:
+			return exprTypmod(((const JsonCoercion *) expr)->expr);
 		default:
 			break;
 	}
@@ -903,6 +918,24 @@ exprCollation(const Node *expr)
 		case T_PlaceHolderVar:
 			coll = exprCollation((Node *) ((const PlaceHolderVar *) expr)->phexpr);
 			break;
+		case T_JsonValueExpr:
+			coll = exprCollation((Node *) ((const JsonValueExpr *) expr)->expr);
+			break;
+		case T_JsonExpr:
+			{
+				JsonExpr *jexpr = (JsonExpr *) expr;
+				JsonCoercion *coercion = jexpr->result_coercion;
+
+				if (!coercion)
+					coll = InvalidOid;
+				else if (coercion->expr)
+					coll = exprCollation(coercion->expr);
+				else if (coercion->via_io || coercion->via_populate)
+					coll = coercion->collation;
+				else
+					coll = InvalidOid;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			coll = InvalidOid;	/* keep compiler quiet */
@@ -1104,6 +1137,25 @@ exprSetCollation(Node *expr, Oid collation)
 			Assert(!OidIsValid(collation)); /* result is always an integer
 											 * type */
 			break;
+		case T_JsonValueExpr:
+			exprSetCollation((Node *) ((const JsonValueExpr *) expr)->expr,
+							 collation);
+			break;
+		case T_JsonExpr:
+			{
+				JsonExpr *jexpr = (JsonExpr *) expr;
+				JsonCoercion *coercion = jexpr->result_coercion;
+
+				if (!coercion)
+					Assert(!OidIsValid(collation));
+				else if (coercion->expr)
+					exprSetCollation(coercion->expr, collation);
+				else if (coercion->via_io || coercion->via_populate)
+					coercion->collation = collation;
+				else
+					Assert(!OidIsValid(collation));
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			break;
@@ -1544,6 +1596,18 @@ exprLocation(const Node *expr)
 		case T_PartitionRangeDatum:
 			loc = ((const PartitionRangeDatum *) expr)->location;
 			break;
+		case T_JsonValueExpr:
+			loc = exprLocation((Node *) ((const JsonValueExpr *) expr)->expr);
+			break;
+		case T_JsonExpr:
+			{
+				const JsonExpr *jsexpr = (const JsonExpr *) expr;
+
+				/* consider both function name and leftmost arg */
+				loc = leftmostLoc(jsexpr->location,
+								  exprLocation(jsexpr->raw_expr));
+			}
+			break;
 		default:
 			/* for any other node type it's just unknown... */
 			loc = -1;
@@ -2218,6 +2282,57 @@ expression_tree_walker(Node *node,
 					return true;
 			}
 			break;
+		case T_JsonValueExpr:
+			return walker(((JsonValueExpr *) node)->expr, context);
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+
+				if (walker(jexpr->raw_expr, context))
+					return true;
+				if (walker(jexpr->formatted_expr, context))
+					return true;
+				if (walker(jexpr->result_coercion, context))
+					return true;
+				if (walker(jexpr->passing.values, context))
+					return true;
+				/* we assume walker doesn't care about passing.names */
+				if (walker(jexpr->on_empty.default_expr, context))
+					return true;
+				if (walker(jexpr->on_error.default_expr, context))
+					return true;
+				if (walker(jexpr->coercions, context))
+					return true;
+			}
+			break;
+		case T_JsonCoercion:
+			return walker(((JsonCoercion *) node)->expr, context);
+		case T_JsonItemCoercions:
+			{
+				JsonItemCoercions *coercions = (JsonItemCoercions *) node;
+
+				if (walker(coercions->null, context))
+					return true;
+				if (walker(coercions->string, context))
+					return true;
+				if (walker(coercions->numeric, context))
+					return true;
+				if (walker(coercions->boolean, context))
+					return true;
+				if (walker(coercions->date, context))
+					return true;
+				if (walker(coercions->time, context))
+					return true;
+				if (walker(coercions->timetz, context))
+					return true;
+				if (walker(coercions->timestamp, context))
+					return true;
+				if (walker(coercions->timestamptz, context))
+					return true;
+				if (walker(coercions->composite, context))
+					return true;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
@@ -3035,6 +3150,65 @@ expression_tree_mutator(Node *node,
 				return (Node *) newnode;
 			}
 			break;
+		case T_JsonValueExpr:
+			{
+				JsonValueExpr *jve = (JsonValueExpr *) node;
+				JsonValueExpr *newnode;
+
+				FLATCOPY(newnode, jve, JsonValueExpr);
+				MUTATE(newnode->expr, jve->expr, Expr *);
+
+				return (Node *) newnode;
+			}
+			break;
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+				JsonExpr    *newnode;
+
+				FLATCOPY(newnode, jexpr, JsonExpr);
+				MUTATE(newnode->raw_expr, jexpr->path_spec, Node *);
+				MUTATE(newnode->raw_expr, jexpr->raw_expr, Node *);
+				MUTATE(newnode->formatted_expr, jexpr->formatted_expr, Node *);
+				MUTATE(newnode->result_coercion, jexpr->result_coercion, JsonCoercion *);
+				MUTATE(newnode->passing.values, jexpr->passing.values, List *);
+				/* assume mutator does not care about passing.names */
+				MUTATE(newnode->on_empty.default_expr,
+					   jexpr->on_empty.default_expr, Node *);
+				MUTATE(newnode->on_error.default_expr,
+					   jexpr->on_error.default_expr, Node *);
+				return (Node *) newnode;
+			}
+			break;
+		case T_JsonCoercion:
+			{
+				JsonCoercion *coercion = (JsonCoercion *) node;
+				JsonCoercion *newnode;
+
+				FLATCOPY(newnode, coercion, JsonCoercion);
+				MUTATE(newnode->expr, coercion->expr, Node *);
+				return (Node *) newnode;
+			}
+			break;
+		case T_JsonItemCoercions:
+			{
+				JsonItemCoercions *coercions = (JsonItemCoercions *) node;
+				JsonItemCoercions *newnode;
+
+				FLATCOPY(newnode, coercions, JsonItemCoercions);
+				MUTATE(newnode->null, coercions->null, JsonCoercion *);
+				MUTATE(newnode->string, coercions->string, JsonCoercion *);
+				MUTATE(newnode->numeric, coercions->numeric, JsonCoercion *);
+				MUTATE(newnode->boolean, coercions->boolean, JsonCoercion *);
+				MUTATE(newnode->date, coercions->date, JsonCoercion *);
+				MUTATE(newnode->time, coercions->time, JsonCoercion *);
+				MUTATE(newnode->timetz, coercions->timetz, JsonCoercion *);
+				MUTATE(newnode->timestamp, coercions->timestamp, JsonCoercion *);
+				MUTATE(newnode->timestamptz, coercions->timestamptz, JsonCoercion *);
+				MUTATE(newnode->composite, coercions->composite, JsonCoercion *);
+				return (Node *) newnode;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
@@ -3679,6 +3853,121 @@ raw_expression_tree_walker(Node *node,
 			break;
 		case T_CommonTableExpr:
 			return walker(((CommonTableExpr *) node)->ctequery, context);
+		case T_JsonValueExpr:
+			return walker(((JsonValueExpr *) node)->expr, context);
+		case T_JsonOutput:
+			return walker(((JsonOutput *) node)->typename, context);
+		case T_JsonKeyValue:
+			{
+				JsonKeyValue *jkv = (JsonKeyValue *) node;
+
+				if (walker(jkv->key, context))
+					return true;
+				if (walker(jkv->value, context))
+					return true;
+			}
+			break;
+		case T_JsonObjectCtor:
+			{
+				JsonObjectCtor *joc = (JsonObjectCtor *) node;
+
+				if (walker(joc->output, context))
+					return true;
+				if (walker(joc->exprs, context))
+					return true;
+			}
+			break;
+		case T_JsonArrayCtor:
+			{
+				JsonArrayCtor *jac = (JsonArrayCtor *) node;
+
+				if (walker(jac->output, context))
+					return true;
+				if (walker(jac->exprs, context))
+					return true;
+			}
+			break;
+		case T_JsonObjectAgg:
+			{
+				JsonObjectAgg *joa = (JsonObjectAgg *) node;
+
+				if (walker(joa->ctor.output, context))
+					return true;
+				if (walker(joa->ctor.agg_order, context))
+					return true;
+				if (walker(joa->ctor.agg_filter, context))
+					return true;
+				if (walker(joa->ctor.over, context))
+					return true;
+				if (walker(joa->arg, context))
+					return true;
+			}
+			break;
+		case T_JsonArrayAgg:
+			{
+				JsonArrayAgg *jaa = (JsonArrayAgg *) node;
+
+				if (walker(jaa->ctor.output, context))
+					return true;
+				if (walker(jaa->ctor.agg_order, context))
+					return true;
+				if (walker(jaa->ctor.agg_filter, context))
+					return true;
+				if (walker(jaa->ctor.over, context))
+					return true;
+				if (walker(jaa->arg, context))
+					return true;
+			}
+			break;
+		case T_JsonArrayQueryCtor:
+			{
+				JsonArrayQueryCtor *jaqc = (JsonArrayQueryCtor *) node;
+
+				if (walker(jaqc->output, context))
+					return true;
+				if (walker(jaqc->query, context))
+					return true;
+			}
+			break;
+		case T_JsonIsPredicate:
+			return walker(((JsonIsPredicate *) node)->expr, context);
+		case T_JsonArgument:
+			return walker(((JsonArgument *) node)->val, context);
+		case T_JsonCommon:
+			{
+				JsonCommon *jc = (JsonCommon *) node;
+
+				if (walker(jc->expr, context))
+					return true;
+				if (walker(jc->pathspec, context))
+					return true;
+				if (walker(jc->passing, context))
+					return true;
+			}
+			break;
+		case T_JsonBehavior:
+			{
+				JsonBehavior *jb = (JsonBehavior *) node;
+
+				if (jb->btype == JSON_BEHAVIOR_DEFAULT &&
+					walker(jb->default_expr, context))
+					return true;
+			}
+			break;
+		case T_JsonFuncExpr:
+			{
+				JsonFuncExpr *jfe = (JsonFuncExpr *) node;
+
+				if (walker(jfe->common, context))
+					return true;
+				if (jfe->output && walker(jfe->output, context))
+					return true;
+				if (walker(jfe->on_empty, context))
+					return true;
+				if (walker(jfe->on_error, context))
+					return true;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 3862bad..ca2de9f 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1713,6 +1713,98 @@ _outOnConflictExpr(StringInfo str, const OnConflictExpr *node)
 	WRITE_NODE_FIELD(exclRelTlist);
 }
 
+static void
+_outJsonValueExpr(StringInfo str, const JsonValueExpr *node)
+{
+	WRITE_NODE_TYPE("JSONVALUEEXPR");
+
+	WRITE_NODE_FIELD(expr);
+	WRITE_ENUM_FIELD(format.type, JsonFormatType);
+	WRITE_ENUM_FIELD(format.encoding, JsonEncoding);
+	WRITE_LOCATION_FIELD(format.location);
+}
+
+static void
+_outJsonCtorOpts(StringInfo str, const JsonCtorOpts *node)
+{
+	WRITE_NODE_TYPE("JSONCTOROPTS");
+
+	WRITE_ENUM_FIELD(returning.format.type, JsonFormatType);
+	WRITE_ENUM_FIELD(returning.format.encoding, JsonEncoding);
+	WRITE_LOCATION_FIELD(returning.format.location);
+	WRITE_OID_FIELD(returning.typid);
+	WRITE_INT_FIELD(returning.typmod);
+	WRITE_BOOL_FIELD(unique);
+	WRITE_BOOL_FIELD(absent_on_null);
+}
+
+static void
+_outJsonExpr(StringInfo str, const JsonExpr *node)
+{
+	WRITE_NODE_TYPE("JSONEXPR");
+
+	WRITE_ENUM_FIELD(op, JsonExprOp);
+	WRITE_NODE_FIELD(raw_expr);
+	WRITE_NODE_FIELD(formatted_expr);
+	WRITE_NODE_FIELD(result_coercion);
+	WRITE_ENUM_FIELD(format.type, JsonFormatType);
+	WRITE_ENUM_FIELD(format.encoding, JsonEncoding);
+	WRITE_LOCATION_FIELD(format.location);
+	WRITE_NODE_FIELD(path_spec);
+	WRITE_NODE_FIELD(passing.values);
+	WRITE_NODE_FIELD(passing.names);
+	WRITE_ENUM_FIELD(returning.format.type, JsonFormatType);
+	WRITE_ENUM_FIELD(returning.format.encoding, JsonEncoding);
+	WRITE_LOCATION_FIELD(returning.format.location);
+	WRITE_OID_FIELD(returning.typid);
+	WRITE_INT_FIELD(returning.typmod);
+	WRITE_ENUM_FIELD(on_error.btype, JsonBehaviorType);
+	WRITE_NODE_FIELD(on_error.default_expr);
+	WRITE_ENUM_FIELD(on_empty.btype, JsonBehaviorType);
+	WRITE_NODE_FIELD(on_empty.default_expr);
+	WRITE_NODE_FIELD(coercions);
+	WRITE_ENUM_FIELD(wrapper, JsonWrapper);
+	WRITE_BOOL_FIELD(omit_quotes);
+	WRITE_LOCATION_FIELD(location);
+}
+
+static void
+_outJsonCoercion(StringInfo str, const JsonCoercion *node)
+{
+	WRITE_NODE_TYPE("JSONCOERCION");
+
+	WRITE_NODE_FIELD(expr);
+	WRITE_BOOL_FIELD(via_populate);
+	WRITE_BOOL_FIELD(via_io);
+	WRITE_OID_FIELD(collation);
+}
+
+static void
+_outJsonItemCoercions(StringInfo str, const JsonItemCoercions *node)
+{
+	WRITE_NODE_TYPE("JSONITEMCOERCIONS");
+
+	WRITE_NODE_FIELD(null);
+	WRITE_NODE_FIELD(string);
+	WRITE_NODE_FIELD(numeric);
+	WRITE_NODE_FIELD(boolean);
+	WRITE_NODE_FIELD(date);
+	WRITE_NODE_FIELD(time);
+	WRITE_NODE_FIELD(timetz);
+	WRITE_NODE_FIELD(timestamp);
+	WRITE_NODE_FIELD(timestamptz);
+	WRITE_NODE_FIELD(composite);
+}
+
+static void
+_outJsonIsPredicateOpts(StringInfo str, const JsonIsPredicateOpts *node)
+{
+	WRITE_NODE_TYPE("JSONISOPTS");
+
+	WRITE_ENUM_FIELD(value_type, JsonValueType);
+	WRITE_BOOL_FIELD(unique_keys);
+}
+
 /*****************************************************************************
  *
  *	Stuff from relation.h.
@@ -4265,6 +4357,24 @@ outNode(StringInfo str, const void *obj)
 			case T_PartitionRangeDatum:
 				_outPartitionRangeDatum(str, obj);
 				break;
+			case T_JsonValueExpr:
+				_outJsonValueExpr(str, obj);
+				break;
+			case T_JsonCtorOpts:
+				_outJsonCtorOpts(str, obj);
+				break;
+			case T_JsonIsPredicateOpts:
+				_outJsonIsPredicateOpts(str, obj);
+				break;
+			case T_JsonExpr:
+				_outJsonExpr(str, obj);
+				break;
+			case T_JsonCoercion:
+				_outJsonCoercion(str, obj);
+				break;
+			case T_JsonItemCoercions:
+				_outJsonItemCoercions(str, obj);
+				break;
 
 			default:
 
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 745d3f3..620c878 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1335,6 +1335,127 @@ _readOnConflictExpr(void)
 }
 
 /*
+ * _readJsonValueExpr
+ */
+static JsonValueExpr *
+_readJsonValueExpr(void)
+{
+	READ_LOCALS(JsonValueExpr);
+
+	READ_NODE_FIELD(expr);
+	READ_ENUM_FIELD(format.type, JsonFormatType);
+	READ_ENUM_FIELD(format.encoding, JsonEncoding);
+	READ_LOCATION_FIELD(format.location);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonCtorOpts
+ */
+static JsonCtorOpts *
+_readJsonCtorOpts(void)
+{
+	READ_LOCALS(JsonCtorOpts);
+	READ_ENUM_FIELD(returning.format.type, JsonFormatType);
+	READ_ENUM_FIELD(returning.format.encoding, JsonEncoding);
+	READ_LOCATION_FIELD(returning.format.location);
+	READ_OID_FIELD(returning.typid);
+	READ_INT_FIELD(returning.typmod);
+	READ_BOOL_FIELD(unique);
+	READ_BOOL_FIELD(absent_on_null);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonExpr
+ */
+static JsonExpr *
+_readJsonExpr(void)
+{
+	READ_LOCALS(JsonExpr);
+
+	READ_ENUM_FIELD(op, JsonExprOp);
+	READ_NODE_FIELD(raw_expr);
+	READ_NODE_FIELD(formatted_expr);
+	READ_NODE_FIELD(result_coercion);
+	READ_ENUM_FIELD(format.type, JsonFormatType);
+	READ_ENUM_FIELD(format.encoding, JsonEncoding);
+	READ_LOCATION_FIELD(format.location);
+	READ_NODE_FIELD(path_spec);
+	READ_NODE_FIELD(passing.values);
+	READ_NODE_FIELD(passing.names);
+	READ_ENUM_FIELD(returning.format.type, JsonFormatType);
+	READ_ENUM_FIELD(returning.format.encoding, JsonEncoding);
+	READ_LOCATION_FIELD(returning.format.location);
+	READ_OID_FIELD(returning.typid);
+	READ_INT_FIELD(returning.typmod);
+	READ_ENUM_FIELD(on_error.btype, JsonBehaviorType);
+	READ_NODE_FIELD(on_error.default_expr);
+	READ_ENUM_FIELD(on_empty.btype, JsonBehaviorType);
+	READ_NODE_FIELD(on_empty.default_expr);
+	READ_NODE_FIELD(coercions);
+	READ_ENUM_FIELD(wrapper, JsonWrapper);
+	READ_BOOL_FIELD(omit_quotes);
+	READ_LOCATION_FIELD(location);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonCoercion
+ */
+static JsonCoercion *
+_readJsonCoercion(void)
+{
+	READ_LOCALS(JsonCoercion);
+
+	READ_NODE_FIELD(expr);
+	READ_BOOL_FIELD(via_populate);
+	READ_BOOL_FIELD(via_io);
+	READ_OID_FIELD(collation);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonItemCoercions
+ */
+static JsonItemCoercions *
+_readJsonItemCoercions(void)
+{
+	READ_LOCALS(JsonItemCoercions);
+
+	READ_NODE_FIELD(null);
+	READ_NODE_FIELD(string);
+	READ_NODE_FIELD(numeric);
+	READ_NODE_FIELD(boolean);
+	READ_NODE_FIELD(date);
+	READ_NODE_FIELD(time);
+	READ_NODE_FIELD(timetz);
+	READ_NODE_FIELD(timestamp);
+	READ_NODE_FIELD(timestamptz);
+	READ_NODE_FIELD(composite);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonIsPredicateOpts
+ */
+static JsonIsPredicateOpts *
+_readJsonIsPredicateOpts()
+{
+	READ_LOCALS(JsonIsPredicateOpts);
+
+	READ_ENUM_FIELD(value_type, JsonValueType);
+	READ_BOOL_FIELD(unique_keys);
+
+	READ_DONE();
+}
+
+/*
  *	Stuff from parsenodes.h.
  */
 
@@ -2689,6 +2810,18 @@ parseNodeString(void)
 		return_value = _readPartitionBoundSpec();
 	else if (MATCH("PARTITIONRANGEDATUM", 19))
 		return_value = _readPartitionRangeDatum();
+	else if (MATCH("JSONVALUEEXPR", 13))
+		return_value = _readJsonValueExpr();
+	else if (MATCH("JSONCTOROPTS", 12))
+		return_value = _readJsonCtorOpts();
+	else if (MATCH("JSONISOPTS", 10))
+		return_value = _readJsonIsPredicateOpts();
+	else if (MATCH("JSONEXPR", 8))
+		return_value = _readJsonExpr();
+	else if (MATCH("JSONCOERCION", 12))
+		return_value = _readJsonCoercion();
+	else if (MATCH("JSONITEMCOERCIONS", 17))
+		return_value = _readJsonItemCoercions();
 	else
 	{
 		elog(ERROR, "badly formatted node string \"%.32s\"...", token);
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index d8db0b2..0f053a8 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -3907,7 +3907,8 @@ cost_qual_eval_walker(Node *node, cost_qual_eval_context *context)
 			 IsA(node, SQLValueFunction) ||
 			 IsA(node, XmlExpr) ||
 			 IsA(node, CoerceToDomain) ||
-			 IsA(node, NextValueExpr))
+			 IsA(node, NextValueExpr) ||
+			 IsA(node, JsonExpr))
 	{
 		/* Treat all these as having cost 1 */
 		context->total.per_tuple += cpu_operator_cost;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 8a2e52a..4210296 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -211,6 +211,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	JoinType			jtype;
 	DropBehavior		dbehavior;
 	OnCommitAction		oncommit;
+	JsonFormat			jsformat;
 	List				*list;
 	Node				*node;
 	Value				*value;
@@ -241,6 +242,12 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	PartitionSpec		*partspec;
 	PartitionBoundSpec	*partboundspec;
 	RoleSpec			*rolespec;
+	JsonBehavior		*jsbehavior;
+	struct {
+		JsonBehavior		*on_empty;
+		JsonBehavior		*on_error;
+	} 					on_behavior;
+	JsonQuotes			js_quotes;
 }
 
 %type <node>	stmt schema_stmt
@@ -583,6 +590,72 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <list>		hash_partbound partbound_datum_list range_datum_list
 %type <defelt>		hash_partbound_elem
 
+%type <node>		json_value_expr
+					json_func_expr
+					json_value_func_expr
+					json_query_expr
+					json_exists_predicate
+					json_api_common_syntax
+					json_context_item
+					json_argument
+					json_output_clause_opt
+					json_value_constructor
+					json_object_constructor
+					json_object_constructor_args_opt
+					json_object_args
+					json_object_ctor_args_opt
+					json_object_func_args
+					json_array_constructor
+					json_name_and_value
+					json_aggregate_func
+					json_object_aggregate_constructor
+					json_array_aggregate_constructor
+					json_path_specification
+
+%type <list>		json_arguments
+					json_passing_clause_opt
+					json_name_and_value_list
+					json_value_expr_list
+					json_array_aggregate_order_by_clause_opt
+
+%type <typnam>		json_returning_clause_opt
+
+%type <str>			json_table_path_name
+					json_as_path_name_clause_opt
+
+%type <ival>		json_encoding
+					json_encoding_clause_opt
+					json_wrapper_clause_opt
+					json_wrapper_behavior
+					json_conditional_or_unconditional_opt
+					json_predicate_type_constraint_opt
+
+%type <jsformat>	json_format_clause_opt
+					json_representation
+
+%type <jsbehavior>	json_behavior_error
+					json_behavior_null
+					json_behavior_true
+					json_behavior_false
+					json_behavior_unknown
+					json_behavior_empty_array
+					json_behavior_empty_object
+					json_behavior_default
+					json_value_behavior
+					json_query_behavior
+					json_exists_error_behavior
+					json_exists_error_clause_opt
+
+%type <on_behavior> json_value_on_behavior_clause_opt
+					json_query_on_behavior_clause_opt
+
+%type <js_quotes>	json_quotes_behavior
+					json_quotes_clause_opt
+
+%type <boolean>		json_key_uniqueness_constraint_opt
+					json_object_constructor_null_clause_opt
+					json_array_constructor_null_clause_opt
+
 /*
  * Non-keyword token types.  These are hard-wired into the "flex" lexer.
  * They must be listed first so that their numeric codes do not depend on
@@ -605,7 +678,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
  */
 
 /* ordinary key words in alphabetical order */
-%token <keyword> ABORT_P ABSOLUTE_P ACCESS ACTION ADD_P ADMIN AFTER
+%token <keyword> ABORT_P ABSENT ABSOLUTE_P ACCESS ACTION ADD_P ADMIN AFTER
 	AGGREGATE ALL ALSO ALTER ALWAYS ANALYSE ANALYZE AND ANY ARRAY AS ASC
 	ASSERTION ASSIGNMENT ASYMMETRIC AT ATTACH ATTRIBUTE AUTHORIZATION
 
@@ -615,8 +688,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	CACHE CALL CALLED CASCADE CASCADED CASE CAST CATALOG_P CHAIN CHAR_P
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLLATION COLUMN COLUMNS COMMENT COMMENTS COMMIT
-	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
-	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
+	COMMITTED CONCURRENTLY CONDITIONAL CONFIGURATION CONFLICT CONNECTION
+	CONSTRAINT CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
 	CROSS CSV CUBE CURRENT_P
 	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
@@ -626,12 +699,12 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	DETACH DICTIONARY DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P
 	DOUBLE_P DROP
 
-	EACH ELSE ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ESCAPE EVENT EXCEPT
-	EXCLUDE EXCLUDING EXCLUSIVE EXECUTE EXISTS EXPLAIN
+	EACH ELSE EMPTY_P ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ERROR_P ESCAPE
+	EVENT EXCEPT EXCLUDE EXCLUDING EXCLUSIVE EXECUTE EXISTS EXPLAIN
 	EXTENSION EXTERNAL EXTRACT
 
 	FALSE_P FAMILY FETCH FILTER FIRST_P FLOAT_P FOLLOWING FOR
-	FORCE FOREIGN FORWARD FREEZE FROM FULL FUNCTION FUNCTIONS
+	FORCE FOREIGN FORMAT FORWARD FREEZE FROM FULL FUNCTION FUNCTIONS
 
 	GENERATED GLOBAL GRANT GRANTED GREATEST GROUP_P GROUPING GROUPS
 
@@ -642,9 +715,10 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
 	INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
 
-	JOIN
+	JOIN JSON JSON_ARRAY JSON_ARRAYAGG JSON_EXISTS JSON_OBJECT JSON_OBJECTAGG
+	JSON_QUERY JSON_VALUE
 
-	KEY
+	KEY KEYS KEEP
 
 	LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
 	LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
@@ -656,7 +730,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	NOT NOTHING NOTIFY NOTNULL NOWAIT NULL_P NULLIF
 	NULLS_P NUMERIC
 
-	OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OPTIONS OR
+	OBJECT_P OF OFF OFFSET OIDS OLD OMIT ON ONLY OPERATOR OPTION OPTIONS OR
 	ORDER ORDINALITY OTHERS OUT_P OUTER_P
 	OVER OVERLAPS OVERLAY OVERRIDING OWNED OWNER
 
@@ -664,17 +738,17 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	POSITION PRECEDING PRECISION PRESERVE PREPARE PREPARED PRIMARY
 	PRIOR PRIVILEGES PROCEDURAL PROCEDURE PROCEDURES PROGRAM PUBLICATION
 
-	QUOTE
+	QUOTE QUOTES
 
 	RANGE READ REAL REASSIGN RECHECK RECURSIVE REF REFERENCES REFERENCING
 	REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA
 	RESET RESTART RESTRICT RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
 	ROUTINE ROUTINES ROW ROWS RULE
 
-	SAVEPOINT SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT SEQUENCE SEQUENCES
-	SERIALIZABLE SERVER SESSION SESSION_USER SET SETS SETOF SHARE SHOW
-	SIMILAR SIMPLE SKIP SMALLINT SNAPSHOT SOME SQL_P STABLE STANDALONE_P
-	START STATEMENT STATISTICS STDIN STDOUT STORAGE STRICT_P STRIP_P
+	SAVEPOINT SCALAR SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT
+	SEQUENCE SEQUENCES SERIALIZABLE SERVER SESSION SESSION_USER SET SETS SETOF
+	SHARE SHOW SIMILAR SIMPLE SKIP SMALLINT SNAPSHOT SOME SQL_P STABLE STANDALONE_P
+	START STATEMENT STATISTICS STDIN STDOUT STORAGE STRICT_P STRING STRIP_P
 	SUBSCRIPTION SUBSTRING SYMMETRIC SYSID SYSTEM_P
 
 	TABLE TABLES TABLESAMPLE TABLESPACE TEMP TEMPLATE TEMPORARY TEXT_P THEN
@@ -682,8 +756,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	TREAT TRIGGER TRIM TRUE_P
 	TRUNCATE TRUSTED TYPE_P TYPES_P
 
-	UNBOUNDED UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN UNLISTEN UNLOGGED
-	UNTIL UPDATE USER USING
+	UNBOUNDED UNCOMMITTED UNCONDITIONAL UNENCRYPTED UNION UNIQUE UNKNOWN
+	UNLISTEN UNLOGGED UNTIL UPDATE USER USING
 
 	VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
 	VERBOSE VERSION_P VIEW VIEWS VOLATILE
@@ -707,11 +781,11 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
  * as NOT, at least with respect to their left-hand subexpression.
  * NULLS_LA and WITH_LA are needed to make the grammar LALR(1).
  */
-%token		NOT_LA NULLS_LA WITH_LA
-
+%token		NOT_LA NULLS_LA WITH_LA WITH_LA_UNIQUE WITHOUT_LA
 
 /* Precedence: lowest to highest */
 %nonassoc	SET				/* see relation_expr_opt_alias */
+%right		FORMAT
 %left		UNION EXCEPT
 %left		INTERSECT
 %left		OR
@@ -750,6 +824,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
  * blame any funny behavior of UNBOUNDED on the SQL standard, though.
  */
 %nonassoc	UNBOUNDED		/* ideally should have same precedence as IDENT */
+%nonassoc	ERROR_P EMPTY_P DEFAULT ABSENT /* JSON error/empty behavior */
+%nonassoc	FALSE_P KEEP OMIT PASSING TRUE_P UNKNOWN
 %nonassoc	IDENT GENERATED NULL_P PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
 %left		Op OPERATOR		/* multi-character ops and user-defined operators */
 %left		'+' '-'
@@ -774,6 +850,9 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 /* kluge to keep xml_whitespace_option from causing shift/reduce conflicts */
 %right		PRESERVE STRIP_P
 
+%nonassoc	empty_json_unique
+%left		WITHOUT WITH_LA_UNIQUE
+
 %%
 
 /*
@@ -12773,7 +12852,7 @@ ConstInterval:
 
 opt_timezone:
 			WITH_LA TIME ZONE						{ $$ = true; }
-			| WITHOUT TIME ZONE						{ $$ = false; }
+			| WITHOUT_LA TIME ZONE					{ $$ = false; }
 			| /*EMPTY*/								{ $$ = false; }
 		;
 
@@ -13274,6 +13353,48 @@ a_expr:		c_expr									{ $$ = $1; }
 												 list_make1($1), @2),
 									 @2);
 				}
+			| a_expr
+				IS JSON
+					json_predicate_type_constraint_opt
+					json_key_uniqueness_constraint_opt		%prec IS
+				{
+					JsonFormat format = { JS_FORMAT_DEFAULT, JS_ENC_DEFAULT, -1 };
+					$$ = makeJsonIsPredicate($1, format, $4, $5);
+				}
+			/*
+			 * Required by standard, but it would conflict with expressions
+			 * like: 'str' || format(...)
+			| a_expr
+				FORMAT json_representation
+				IS JSON
+					json_predicate_type_constraint_opt
+					json_key_uniqueness_constraint_opt		%prec FORMAT
+				{
+					$3.location = @2;
+					$$ = makeJsonIsPredicate($1, $3, $6, $7);
+				}
+			*/
+			| a_expr
+				IS NOT JSON
+					json_predicate_type_constraint_opt
+					json_key_uniqueness_constraint_opt		%prec IS
+				{
+					JsonFormat format = { JS_FORMAT_DEFAULT, JS_ENC_DEFAULT, -1 };
+					$$ = makeNotExpr(makeJsonIsPredicate($1, format, $5, $6), @1);
+				}
+			/*
+			 * Required by standard, but it would conflict with expressions
+			 * like: 'str' || format(...)
+			| a_expr
+				FORMAT json_representation
+				IS NOT JSON
+					json_predicate_type_constraint_opt
+					json_key_uniqueness_constraint_opt		%prec FORMAT
+				{
+					$3.location = @2;
+					$$ = makeNotExpr(makeJsonIsPredicate($1, $3, $7, $8), @1);
+				}
+			*/
 			| DEFAULT
 				{
 					/*
@@ -13366,6 +13487,25 @@ b_expr:		c_expr
 				}
 		;
 
+json_predicate_type_constraint_opt:
+			VALUE_P									{ $$ = JS_TYPE_ANY; }
+			| ARRAY									{ $$ = JS_TYPE_ARRAY; }
+			| OBJECT_P								{ $$ = JS_TYPE_OBJECT; }
+			| SCALAR								{ $$ = JS_TYPE_SCALAR; }
+			| /* EMPTY */							{ $$ = JS_TYPE_ANY; }
+		;
+
+json_key_uniqueness_constraint_opt:
+			WITH_LA_UNIQUE UNIQUE opt_keys			{ $$ = true; }
+			| WITHOUT UNIQUE opt_keys				{ $$ = false; }
+			| /* EMPTY */ %prec empty_json_unique	{ $$ = false; }
+		;
+
+opt_keys:
+			KEYS									{ }
+			| /* EMPTY */							{ }
+		;
+
 /*
  * Productions that can be used in both a_expr and b_expr.
  *
@@ -13626,6 +13766,13 @@ func_expr: func_application within_group_clause filter_clause over_clause
 					n->over = $4;
 					$$ = (Node *) n;
 				}
+			| json_aggregate_func filter_clause over_clause
+				{
+					JsonAggCtor *n = (JsonAggCtor *) $1;
+					n->agg_filter = $2;
+					n->over = $3;
+					$$ = (Node *) $1;
+				}
 			| func_expr_common_subexpr
 				{ $$ = $1; }
 		;
@@ -13639,6 +13786,7 @@ func_expr: func_application within_group_clause filter_clause over_clause
 func_expr_windowless:
 			func_application						{ $$ = $1; }
 			| func_expr_common_subexpr				{ $$ = $1; }
+			| json_aggregate_func					{ $$ = $1; }
 		;
 
 /*
@@ -13860,6 +14008,8 @@ func_expr_common_subexpr:
 					n->location = @1;
 					$$ = (Node *)n;
 				}
+			| json_func_expr
+				{ $$ = $1; }
 		;
 
 /*
@@ -14548,6 +14698,495 @@ opt_asymmetric: ASYMMETRIC
 			| /*EMPTY*/
 		;
 
+/* SQL/JSON support */
+json_func_expr:
+			json_value_func_expr
+			| json_query_expr
+			| json_exists_predicate
+			| json_value_constructor
+		;
+
+
+json_value_func_expr:
+			JSON_VALUE '('
+				json_api_common_syntax
+				json_returning_clause_opt
+				json_value_on_behavior_clause_opt
+			')'
+				{
+					JsonFuncExpr *n = makeNode(JsonFuncExpr);
+					n->op = IS_JSON_VALUE;
+					n->common = (JsonCommon *) $3;
+					if ($4)
+					{
+						n->output = (JsonOutput *) makeNode(JsonOutput);
+						n->output->typename = $4;
+						n->output->returning.format.location = @4;
+						n->output->returning.format.type = JS_FORMAT_DEFAULT;
+						n->output->returning.format.encoding = JS_ENC_DEFAULT;
+					}
+					else
+						n->output = NULL;
+					n->on_empty = $5.on_empty;
+					n->on_error = $5.on_error;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_api_common_syntax:
+			json_context_item ',' json_path_specification
+			json_as_path_name_clause_opt
+			json_passing_clause_opt
+				{
+					JsonCommon *n = makeNode(JsonCommon);
+					n->expr = (JsonValueExpr *) $1;
+					n->pathspec = $3;
+					n->pathname = $4;
+					n->passing = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_context_item:
+			json_value_expr							{ $$ = $1; }
+		;
+
+json_path_specification:
+			a_expr									{ $$ = $1; }
+		;
+
+json_as_path_name_clause_opt:
+			 AS json_table_path_name				{ $$ = $2; }
+			 | /* EMPTY */							{ $$ = NULL; }
+		;
+
+json_table_path_name:
+			name									{ $$ = $1; }
+		;
+
+json_passing_clause_opt:
+			PASSING json_arguments					{ $$ = $2; }
+			| /* EMPTY */							{ $$ = NIL; }
+		;
+
+json_arguments:
+			json_argument							{ $$ = list_make1($1); }
+			| json_arguments ',' json_argument		{ $$ = lappend($1, $3); }
+		;
+
+json_argument:
+			json_value_expr AS ColLabel
+			{
+				JsonArgument *n = makeNode(JsonArgument);
+				n->val = (JsonValueExpr *) $1;
+				n->name = $3;
+				$$ = (Node *) n;
+			}
+		;
+
+json_value_expr:
+			a_expr json_format_clause_opt
+			{
+				$$ = (Node *) makeJsonValueExpr((Expr *) $1, $2);
+			}
+		;
+
+json_format_clause_opt:
+			FORMAT json_representation
+				{
+					$$ = $2;
+					$$.location = @1;
+				}
+			| /* EMPTY */
+				{
+					$$.type = JS_FORMAT_DEFAULT;
+					$$.encoding = JS_ENC_DEFAULT;
+					$$.location = -1;
+				}
+		;
+
+json_representation:
+			JSON json_encoding_clause_opt
+				{
+					$$.type = JS_FORMAT_JSON;
+					$$.encoding = $2;
+					$$.location = @1;
+				}
+		/*	| implementation_defined_JSON_representation_option (BSON, AVRO etc) */
+		;
+
+json_encoding_clause_opt:
+			ENCODING json_encoding					{ $$ = $2; }
+			| /* EMPTY */							{ $$ = JS_ENC_DEFAULT; }
+		;
+
+json_encoding:
+			name									{ $$ = makeJsonEncoding($1); }
+	/*
+			| UTF8									{ $$ = JS_ENC_UTF8; }
+			| UTF16									{ $$ = JS_ENC_UTF16; }
+			| UTF32 								{ $$ = JS_ENC_UTF32; }
+	*/
+		;
+
+json_returning_clause_opt:
+			RETURNING Typename						{ $$ = $2; }
+			| /* EMPTY */							{ $$ = NULL; }
+		;
+
+json_behavior_error:
+			ERROR_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_ERROR, NULL); }
+		;
+
+json_behavior_null:
+			NULL_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_NULL, NULL); }
+		;
+
+json_behavior_true:
+			TRUE_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_TRUE, NULL); }
+		;
+
+json_behavior_false:
+			FALSE_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_FALSE, NULL); }
+		;
+
+json_behavior_unknown:
+			UNKNOWN		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_UNKNOWN, NULL); }
+		;
+
+json_behavior_empty_array:
+			EMPTY_P ARRAY	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_EMPTY_ARRAY, NULL); }
+		;
+
+json_behavior_empty_object:
+			EMPTY_P OBJECT_P	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_EMPTY_OBJECT, NULL); }
+		;
+
+json_behavior_default:
+			DEFAULT a_expr	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_DEFAULT, $2); }
+		;
+
+
+json_value_behavior:
+			json_behavior_null
+			| json_behavior_error
+			| json_behavior_default
+		;
+
+json_value_on_behavior_clause_opt:
+			json_value_behavior ON EMPTY_P
+									{ $$.on_empty = $1; $$.on_error = NULL; }
+			| json_value_behavior ON EMPTY_P json_value_behavior ON ERROR_P
+									{ $$.on_empty = $1; $$.on_error = $4; }
+			| json_value_behavior ON ERROR_P
+									{ $$.on_empty = NULL; $$.on_error = $1; }
+			|  /* EMPTY */
+									{ $$.on_empty = NULL; $$.on_error = NULL; }
+		;
+
+json_query_expr:
+			JSON_QUERY '('
+				json_api_common_syntax
+				json_output_clause_opt
+				json_wrapper_clause_opt
+				json_quotes_clause_opt
+				json_query_on_behavior_clause_opt
+			')'
+				{
+					JsonFuncExpr *n = makeNode(JsonFuncExpr);
+					n->op = IS_JSON_QUERY;
+					n->common = (JsonCommon *) $3;
+					n->output = (JsonOutput *) $4;
+					n->wrapper = $5;
+					if (n->wrapper != JSW_NONE && $6 != JS_QUOTES_UNSPEC)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used"),
+								 parser_errposition(@6)));
+					n->omit_quotes = $6 == JS_QUOTES_OMIT;
+					n->on_empty = $7.on_empty;
+					n->on_error = $7.on_error;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_wrapper_clause_opt:
+			json_wrapper_behavior WRAPPER			{ $$ = $1; }
+			| /* EMPTY */							{ $$ = 0; }
+		;
+
+json_wrapper_behavior:
+			WITHOUT array_opt						{ $$ = JSW_NONE; }
+			| WITH json_conditional_or_unconditional_opt array_opt { $$ = $2; }
+		;
+
+array_opt:
+			ARRAY									{ }
+			| /* EMPTY */							{ }
+		;
+
+json_conditional_or_unconditional_opt:
+			CONDITIONAL								{ $$ = JSW_CONDITIONAL; }
+			| UNCONDITIONAL							{ $$ = JSW_UNCONDITIONAL; }
+			| /* EMPTY */							{ $$ = JSW_UNCONDITIONAL; }
+		;
+
+json_quotes_clause_opt:
+			json_quotes_behavior QUOTES json_on_scalar_string_opt { $$ = $1; }
+			| /* EMPTY */							{ $$ = JS_QUOTES_UNSPEC; }
+		;
+
+json_quotes_behavior:
+			KEEP									{ $$ = JS_QUOTES_KEEP; }
+			| OMIT									{ $$ = JS_QUOTES_OMIT; }
+		;
+
+json_on_scalar_string_opt:
+			ON SCALAR STRING						{ }
+			| /* EMPTY */							{ }
+		;
+
+json_query_behavior:
+			json_behavior_error
+			| json_behavior_null
+			| json_behavior_empty_array
+			| json_behavior_empty_object
+		;
+
+json_query_on_behavior_clause_opt:
+			json_query_behavior ON EMPTY_P
+									{ $$.on_empty = $1; $$.on_error = NULL; }
+			| json_query_behavior ON EMPTY_P json_query_behavior ON ERROR_P
+									{ $$.on_empty = $1; $$.on_error = $4; }
+			| json_query_behavior ON ERROR_P
+									{ $$.on_empty = NULL; $$.on_error = $1; }
+			|  /* EMPTY */
+									{ $$.on_empty = NULL; $$.on_error = NULL; }
+		;
+
+
+json_output_clause_opt:
+			RETURNING Typename json_format_clause_opt
+				{
+					JsonOutput *n = makeNode(JsonOutput);
+					n->typename = $2;
+					n->returning.format = $3;
+					$$ = (Node *) n;
+				}
+			| /* EMPTY */								{ $$ = NULL; }
+		;
+
+json_exists_predicate:
+			JSON_EXISTS '('
+				json_api_common_syntax
+				json_exists_error_clause_opt
+			')'
+				{
+					JsonFuncExpr *p = makeNode(JsonFuncExpr);
+					p->op = IS_JSON_EXISTS;
+					p->common = (JsonCommon *) $3;
+					p->on_error = $4;
+					p->location = @1;
+					$$ = (Node *) p;
+				}
+		;
+
+json_exists_error_clause_opt:
+			json_exists_error_behavior ON ERROR_P		{ $$ = $1; }
+			| /* EMPTY */								{ $$ = NULL; }
+		;
+
+json_exists_error_behavior:
+			json_behavior_error
+			| json_behavior_true
+			| json_behavior_false
+			| json_behavior_unknown
+		;
+
+json_value_constructor:
+			json_object_constructor
+			| json_array_constructor
+		;
+
+json_object_constructor:
+			JSON_OBJECT '(' json_object_args ')'
+				{
+					$$ = $3;
+				}
+		;
+
+json_object_args:
+			json_object_ctor_args_opt
+			| json_object_func_args
+		;
+
+json_object_func_args:
+			func_arg_list
+				{
+					List *func = list_make1(makeString("json_object"));
+					$$ = (Node *) makeFuncCall(func, $1, @1);
+				}
+		;
+
+json_object_ctor_args_opt:
+			json_object_constructor_args_opt json_output_clause_opt
+				{
+					JsonObjectCtor *n = (JsonObjectCtor *) $1;
+					n->output = (JsonOutput *) $2;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_object_constructor_args_opt:
+			json_name_and_value_list
+			json_object_constructor_null_clause_opt
+			json_key_uniqueness_constraint_opt
+				{
+					JsonObjectCtor *n = makeNode(JsonObjectCtor);
+					n->exprs = $1;
+					n->absent_on_null = $2;
+					n->unique = $3;
+					$$ = (Node *) n;
+				}
+			| /* EMPTY */
+				{
+					JsonObjectCtor *n = makeNode(JsonObjectCtor);
+					n->exprs = NULL;
+					n->absent_on_null = false;
+					n->unique = false;
+					$$ = (Node *) n;
+				}
+		;
+
+json_name_and_value_list:
+			json_name_and_value
+				{ $$ = list_make1($1); }
+			| json_name_and_value_list ',' json_name_and_value
+				{ $$ = lappend($1, $3); }
+		;
+
+json_name_and_value:
+/* TODO
+			KEY c_expr VALUE_P json_value_expr %prec POSTFIXOP
+				{ $$ = makeJsonKeyValue($2, $4); }
+			|
+*/
+			c_expr VALUE_P json_value_expr
+				{ $$ = makeJsonKeyValue($1, $3); }
+			|
+			a_expr ':' json_value_expr
+				{ $$ = makeJsonKeyValue($1, $3); }
+		;
+
+json_object_constructor_null_clause_opt:
+			NULL_P ON NULL_P					{ $$ = false; }
+			| ABSENT ON NULL_P					{ $$ = true; }
+			| /* EMPTY */						{ $$ = false; }
+		;
+
+json_array_constructor:
+			JSON_ARRAY '('
+				json_value_expr_list
+				json_array_constructor_null_clause_opt
+				json_output_clause_opt
+			')'
+				{
+					JsonArrayCtor *n = makeNode(JsonArrayCtor);
+					n->exprs = $3;
+					n->absent_on_null = $4;
+					n->output = (JsonOutput *) $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| JSON_ARRAY '('
+				select_no_parens
+				/* json_format_clause_opt */
+				/* json_array_constructor_null_clause_opt */
+				json_output_clause_opt
+			')'
+				{
+					JsonArrayQueryCtor *n = makeNode(JsonArrayQueryCtor);
+					n->query = $3;
+					/* n->format = $4; */
+					n->absent_on_null = true /* $5 */;
+					n->output = (JsonOutput *) $4;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| JSON_ARRAY '('
+				json_output_clause_opt
+			')'
+				{
+					JsonArrayCtor *n = makeNode(JsonArrayCtor);
+					n->exprs = NIL;
+					n->absent_on_null = true;
+					n->output = (JsonOutput *) $3;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_value_expr_list:
+			json_value_expr								{ $$ = list_make1($1); }
+			| json_value_expr_list ',' json_value_expr	{ $$ = lappend($1, $3);}
+		;
+
+json_array_constructor_null_clause_opt:
+			NULL_P ON NULL_P						{ $$ = false; }
+			| ABSENT ON NULL_P						{ $$ = true; }
+			| /* EMPTY */							{ $$ = true; }
+		;
+
+json_aggregate_func:
+			json_object_aggregate_constructor
+			| json_array_aggregate_constructor
+		;
+
+json_object_aggregate_constructor:
+			JSON_OBJECTAGG '('
+				json_name_and_value
+				json_object_constructor_null_clause_opt
+				json_key_uniqueness_constraint_opt
+				json_output_clause_opt
+			')'
+				{
+					JsonObjectAgg *n = makeNode(JsonObjectAgg);
+					n->arg = (JsonKeyValue *) $3;
+					n->absent_on_null = $4;
+					n->unique = $5;
+					n->ctor.output = (JsonOutput *) $6;
+					n->ctor.agg_order = NULL;
+					n->ctor.location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_array_aggregate_constructor:
+			JSON_ARRAYAGG '('
+				json_value_expr
+				json_array_aggregate_order_by_clause_opt
+				json_array_constructor_null_clause_opt
+				json_output_clause_opt
+			')'
+				{
+					JsonArrayAgg *n = makeNode(JsonArrayAgg);
+					n->arg = (JsonValueExpr *) $3;
+					n->ctor.agg_order = $4;
+					n->absent_on_null = $5;
+					n->ctor.output = (JsonOutput *) $6;
+					n->ctor.location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_array_aggregate_order_by_clause_opt:
+			ORDER BY sortby_list					{ $$ = $3; }
+			| /* EMPTY */							{ $$ = NIL; }
+		;
 
 /*****************************************************************************
  *
@@ -14941,6 +15580,7 @@ ColLabel:	IDENT									{ $$ = $1; }
  */
 unreserved_keyword:
 			  ABORT_P
+			| ABSENT
 			| ABSOLUTE_P
 			| ACCESS
 			| ACTION
@@ -14977,6 +15617,7 @@ unreserved_keyword:
 			| COMMENTS
 			| COMMIT
 			| COMMITTED
+			| CONDITIONAL
 			| CONFIGURATION
 			| CONFLICT
 			| CONNECTION
@@ -15012,10 +15653,12 @@ unreserved_keyword:
 			| DOUBLE_P
 			| DROP
 			| EACH
+			| EMPTY_P
 			| ENABLE_P
 			| ENCODING
 			| ENCRYPTED
 			| ENUM_P
+			| ERROR_P
 			| ESCAPE
 			| EVENT
 			| EXCLUDE
@@ -15060,7 +15703,10 @@ unreserved_keyword:
 			| INSTEAD
 			| INVOKER
 			| ISOLATION
+			| JSON
+			| KEEP
 			| KEY
+			| KEYS
 			| LABEL
 			| LANGUAGE
 			| LARGE_P
@@ -15098,6 +15744,7 @@ unreserved_keyword:
 			| OFF
 			| OIDS
 			| OLD
+			| OMIT
 			| OPERATOR
 			| OPTION
 			| OPTIONS
@@ -15127,6 +15774,7 @@ unreserved_keyword:
 			| PROGRAM
 			| PUBLICATION
 			| QUOTE
+			| QUOTES
 			| RANGE
 			| READ
 			| REASSIGN
@@ -15155,6 +15803,7 @@ unreserved_keyword:
 			| ROWS
 			| RULE
 			| SAVEPOINT
+			| SCALAR
 			| SCHEMA
 			| SCHEMAS
 			| SCROLL
@@ -15203,6 +15852,7 @@ unreserved_keyword:
 			| TYPES_P
 			| UNBOUNDED
 			| UNCOMMITTED
+			| UNCONDITIONAL
 			| UNENCRYPTED
 			| UNKNOWN
 			| UNLISTEN
@@ -15260,6 +15910,13 @@ col_name_keyword:
 			| INT_P
 			| INTEGER
 			| INTERVAL
+			| JSON_ARRAY
+			| JSON_ARRAYAGG
+			| JSON_EXISTS
+			| JSON_OBJECT
+			| JSON_OBJECTAGG
+			| JSON_QUERY
+			| JSON_VALUE
 			| LEAST
 			| NATIONAL
 			| NCHAR
@@ -15274,6 +15931,7 @@ col_name_keyword:
 			| ROW
 			| SETOF
 			| SMALLINT
+			| STRING
 			| SUBSTRING
 			| TIME
 			| TIMESTAMP
@@ -15311,6 +15969,7 @@ type_func_name_keyword:
 			| CONCURRENTLY
 			| CROSS
 			| CURRENT_SCHEMA
+			| FORMAT
 			| FREEZE
 			| FULL
 			| ILIKE
diff --git a/src/backend/parser/parse_collate.c b/src/backend/parser/parse_collate.c
index 6d34245..e486e7c 100644
--- a/src/backend/parser/parse_collate.c
+++ b/src/backend/parser/parse_collate.c
@@ -667,6 +667,10 @@ assign_collations_walker(Node *node, assign_collations_context *context)
 															&loccontext);
 						}
 						break;
+					case T_JsonExpr:
+						/* Context item and PASSING arguments are already
+						 * marked with collations in parse_expr.c. */
+						break;
 					default:
 
 						/*
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 385e54a..67ee55c 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -15,6 +15,8 @@
 
 #include "postgres.h"
 
+#include "catalog/pg_aggregate.h"
+#include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
@@ -35,6 +37,7 @@
 #include "parser/parse_agg.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
 #include "utils/timestamp.h"
 #include "utils/xml.h"
@@ -121,6 +124,15 @@ static Node *transformWholeRowRef(ParseState *pstate, RangeTblEntry *rte,
 static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
 static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
 static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformJsonObjectCtor(ParseState *pstate, JsonObjectCtor *ctor);
+static Node *transformJsonArrayCtor(ParseState *pstate, JsonArrayCtor *ctor);
+static Node *transformJsonArrayQueryCtor(ParseState *pstate,
+										 JsonArrayQueryCtor *ctor);
+static Node *transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg);
+static Node *transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg);
+static Node *transformJsonIsPredicate(ParseState *pstate, JsonIsPredicate *p);
+static Node *transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *p);
+static Node *transformJsonValueExpr(ParseState *pstate, JsonValueExpr *jve);
 static Node *make_row_comparison_op(ParseState *pstate, List *opname,
 					   List *largs, List *rargs, int location);
 static Node *make_row_distinct_op(ParseState *pstate, List *opname,
@@ -369,6 +381,38 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 				break;
 			}
 
+		case T_JsonObjectCtor:
+			result = transformJsonObjectCtor(pstate, (JsonObjectCtor *) expr);
+			break;
+
+		case T_JsonArrayCtor:
+			result = transformJsonArrayCtor(pstate, (JsonArrayCtor *) expr);
+			break;
+
+		case T_JsonArrayQueryCtor:
+			result = transformJsonArrayQueryCtor(pstate, (JsonArrayQueryCtor *) expr);
+			break;
+
+		case T_JsonObjectAgg:
+			result = transformJsonObjectAgg(pstate, (JsonObjectAgg *) expr);
+			break;
+
+		case T_JsonArrayAgg:
+			result = transformJsonArrayAgg(pstate, (JsonArrayAgg *) expr);
+			break;
+
+		case T_JsonIsPredicate:
+			result = transformJsonIsPredicate(pstate, (JsonIsPredicate *) expr);
+			break;
+
+		case T_JsonFuncExpr:
+			result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
+			break;
+
+		case T_JsonValueExpr:
+			result = transformJsonValueExpr(pstate, (JsonValueExpr *) expr);
+			break;
+
 		default:
 			/* should not reach here */
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -3485,3 +3529,1209 @@ ParseExprKindName(ParseExprKind exprKind)
 	}
 	return "unrecognized expression kind";
 }
+
+/*
+ * Make string Const node from JSON encoding name.
+ *
+ * UTF8 is default encoding.
+ */
+static Const *
+getJsonEncodingConst(JsonFormat *format)
+{
+	JsonEncoding encoding;
+	const char *enc;
+	Name		encname = palloc(sizeof(NameData));
+
+	if (!format ||
+		format->type == JS_FORMAT_DEFAULT ||
+		format->encoding == JS_ENC_DEFAULT)
+		encoding = JS_ENC_UTF8;
+	else
+		encoding = format->encoding;
+
+	switch (encoding)
+	{
+		case JS_ENC_UTF16:
+			enc = "UTF16";
+			break;
+		case JS_ENC_UTF32:
+			enc = "UTF32";
+			break;
+		case JS_ENC_UTF8:
+		default:
+			enc = "UTF8";
+			break;
+	}
+
+	namestrcpy(encname, enc);
+
+	return makeConst(NAMEOID, -1, InvalidOid, NAMEDATALEN,
+					 NameGetDatum(encname), false, false);
+}
+
+/*
+ * Make bytea => text conversion using specified JSON format encoding.
+ */
+static Node *
+makeJsonByteaToTextConversion(Node *expr, JsonFormat *format, int location)
+{
+	Const	   *encoding = getJsonEncodingConst(format);
+	FuncExpr   *fexpr = makeFuncExpr(F_PG_CONVERT_FROM, TEXTOID,
+									 list_make2(expr, encoding),
+									 InvalidOid, InvalidOid,
+									 COERCE_INTERNAL_CAST);
+
+	fexpr->location = location;
+
+	return (Node *) fexpr;
+}
+
+static Node *
+makeCaseTestExpr(Node *expr)
+{
+	CaseTestExpr *placeholder = makeNode(CaseTestExpr);
+
+	placeholder->typeId = exprType(expr);
+	placeholder->typeMod = exprTypmod(expr);
+	placeholder->collation = exprCollation(expr);
+
+	return (Node *) placeholder;
+}
+
+/*
+ * Transform JSON value expression using specified input JSON format or
+ * default format otherwise.
+ */
+static Node *
+transformJsonValueExprExt(ParseState *pstate, JsonValueExpr *ve,
+						  JsonFormatType default_format, bool isarg,
+						  Node **rawexpr)
+{
+	Node	   *expr = transformExprRecurse(pstate, (Node *) ve->expr);
+	JsonFormatType format;
+	Oid			exprtype;
+	int			location;
+	char		typcategory;
+	bool		typispreferred;
+
+	if (exprType(expr) == UNKNOWNOID)
+		expr = coerce_to_specific_type(pstate, expr, TEXTOID, "JSON_VALUE_EXPR");
+
+	exprtype = exprType(expr);
+	location = exprLocation(expr);
+
+	get_type_category_preferred(exprtype, &typcategory, &typispreferred);
+
+	if (rawexpr)
+	{
+		/*
+		 * Save a raw context item expression if it is needed for the isolation
+		 * of error handling in the formatting stage.
+		 */
+		*rawexpr = expr;
+		assign_expr_collations(pstate, expr);
+		expr = makeCaseTestExpr(expr);
+	}
+
+	if (ve->format.type != JS_FORMAT_DEFAULT)
+	{
+		if (ve->format.encoding != JS_ENC_DEFAULT && exprtype != BYTEAOID)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("JSON ENCODING clause is only allowed for bytea input type"),
+					 parser_errposition(pstate, ve->format.location)));
+
+		if (exprtype == JSONOID || exprtype == JSONBOID)
+		{
+			format = JS_FORMAT_DEFAULT;	/* do not format json[b] types */
+			ereport(WARNING,
+					(errmsg("FORMAT JSON has no effect for json and jsonb types")));
+		}
+		else
+			format = ve->format.type;
+	}
+	else if (isarg)
+	{
+		/* Pass SQL/JSON item types directly without conversion to json[b]. */
+		switch (exprtype)
+		{
+			case TEXTOID:
+			case NUMERICOID:
+			case BOOLOID:
+			case INT2OID:
+			case INT4OID:
+			case INT8OID:
+			case FLOAT4OID:
+			case FLOAT8OID:
+			case DATEOID:
+			case TIMEOID:
+			case TIMETZOID:
+			case TIMESTAMPOID:
+			case TIMESTAMPTZOID:
+				return expr;
+
+			default:
+				if (typcategory == TYPCATEGORY_STRING)
+					return coerce_to_specific_type(pstate, expr, TEXTOID,
+												   "JSON_VALUE_EXPR");
+				/* else convert argument to json[b] type */
+				break;
+		}
+
+		format = default_format;
+	}
+	else if (exprtype == JSONOID || exprtype == JSONBOID)
+		format = JS_FORMAT_DEFAULT;	/* do not format json[b] types */
+	else
+		format = default_format;
+
+	if (format != JS_FORMAT_DEFAULT)
+	{
+		Oid			targettype = format == JS_FORMAT_JSONB ? JSONBOID : JSONOID;
+		Node	   *coerced;
+		FuncExpr   *fexpr;
+
+		if (!isarg && exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg(ve->format.type == JS_FORMAT_DEFAULT ?
+							"cannot use non-string types with implicit FORMAT JSON clause" :
+							"cannot use non-string types with explicit FORMAT JSON clause"),
+					 parser_errposition(pstate, ve->format.location >= 0 ?
+										ve->format.location : location)));
+
+		/* Convert encoded JSON text from bytea. */
+		if (format == JS_FORMAT_JSON && exprtype == BYTEAOID)
+		{
+			expr = makeJsonByteaToTextConversion(expr, &ve->format, location);
+			exprtype = TEXTOID;
+		}
+
+		/* Try to coerce to the target type. */
+		coerced = coerce_to_target_type(pstate, expr, exprtype,
+										targettype, -1,
+										COERCION_EXPLICIT,
+										COERCE_INTERNAL_CAST,
+										location);
+
+		if (coerced)
+			expr = coerced;
+		else
+		{
+
+			/* If coercion failed, use to_json()/to_jsonb() functions. */
+			fexpr = makeFuncExpr(targettype == JSONOID ? F_TO_JSON : F_TO_JSONB,
+								 targettype, list_make1(expr),
+								 InvalidOid, InvalidOid,
+								 COERCE_INTERNAL_CAST);
+			fexpr->location = location;
+
+			expr = (Node *) fexpr;
+		}
+
+		ve = copyObject(ve);
+		ve->expr = (Expr *) expr;
+
+		expr = (Node *) ve;
+	}
+
+	return expr;
+}
+
+/*
+ * Transform JSON value expression using FORMAT JSON by default.
+ */
+static Node *
+transformJsonValueExpr(ParseState *pstate, JsonValueExpr *jve)
+{
+	return transformJsonValueExprExt(pstate, jve, JS_FORMAT_JSON, false, NULL);
+}
+
+/*
+ * Transform JSON value expression using unspecified format by default.
+ */
+static Node *
+transformJsonValueExprDefault(ParseState *pstate, JsonValueExpr *jve)
+{
+	return transformJsonValueExprExt(pstate, jve, JS_FORMAT_DEFAULT, false, NULL);
+}
+
+/*
+ * Checks specified output format for its applicability to the target type.
+ */
+static void
+checkJsonOutputFormat(ParseState *pstate, const JsonFormat *format,
+					  Oid targettype, bool allow_format_for_non_strings)
+{
+	if (!allow_format_for_non_strings &&
+		format->type != JS_FORMAT_DEFAULT &&
+		(targettype != BYTEAOID &&
+		 targettype != JSONOID &&
+		 targettype != JSONBOID))
+	{
+		char		typcategory;
+		bool		typispreferred;
+
+		get_type_category_preferred(targettype, &typcategory, &typispreferred);
+
+		if (typcategory != TYPCATEGORY_STRING)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 parser_errposition(pstate, format->location),
+					 errmsg("cannot use JSON format with non-string output types")));
+	}
+
+	if (format->type == JS_FORMAT_JSON)
+	{
+		JsonEncoding enc = format->encoding != JS_ENC_DEFAULT ?
+						   format->encoding : JS_ENC_UTF8;
+
+		if (targettype != BYTEAOID &&
+			format->encoding != JS_ENC_DEFAULT)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 parser_errposition(pstate, format->location),
+					 errmsg("cannot set JSON encoding for non-bytea output types")));
+
+		if (enc != JS_ENC_UTF8)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unsupported JSON encoding"),
+					 errhint("only UTF8 JSON encoding is supported"),
+					 parser_errposition(pstate, format->location)));
+	}
+}
+
+/*
+ * Transform JSON output clause.
+ *
+ * Assigns target type oid and modifier.
+ * Assigns default format or checks specified format for its applicability to
+ * the target type.
+ */
+static void
+transformJsonOutput(ParseState *pstate, const JsonOutput *output,
+					bool allow_format, JsonReturning *ret)
+{
+	/* if output clause is not specified, make default clause value */
+	if (!output)
+	{
+		ret->format.type = JS_FORMAT_DEFAULT;
+		ret->format.encoding = JS_ENC_DEFAULT;
+		ret->format.location = -1;
+		ret->typid = InvalidOid;
+		ret->typmod = -1;
+
+		return;
+	}
+
+	*ret = output->returning;
+
+	typenameTypeIdAndMod(pstate, output->typename, &ret->typid, &ret->typmod);
+
+	if (output->typename->setof)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("returning SETOF types is not supported in SQL/JSON functions")));
+
+	if (ret->format.type == JS_FORMAT_DEFAULT)
+		/* assign JSONB format when returning jsonb, or JSON format otherwise */
+		ret->format.type =
+			ret->typid == JSONBOID ? JS_FORMAT_JSONB : JS_FORMAT_JSON;
+	else
+		checkJsonOutputFormat(pstate, &ret->format, ret->typid, allow_format);
+}
+
+/*
+ * Coerce json[b]-valued function expression to the output type.
+ */
+static Node *
+coerceJsonFuncExpr(ParseState *pstate, Node *expr, JsonReturning *returning,
+				   bool report_error)
+{
+	Node	   *res;
+	int			location;
+	Oid			exprtype = exprType(expr);
+
+	/* if output type is not specified or equals to function type, return */
+	if (!OidIsValid(returning->typid) || returning->typid == exprtype)
+		return expr;
+
+	location = exprLocation(expr);
+
+	if (location < 0)
+		location = returning ? returning->format.location : -1;
+
+	/* special case for RETURNING bytea FORMAT json */
+	if (returning->format.type == JS_FORMAT_JSON &&
+		returning->typid == BYTEAOID)
+	{
+		/* encode json text into bytea using pg_convert_to() */
+		Node	   *texpr = coerce_to_specific_type(pstate, expr, TEXTOID,
+													"JSON_FUNCTION");
+		Const	   *enc = getJsonEncodingConst(&returning->format);
+		FuncExpr   *fexpr = makeFuncExpr(F_PG_CONVERT_TO, BYTEAOID,
+										 list_make2(texpr, enc),
+										 InvalidOid, InvalidOid,
+										 COERCE_INTERNAL_CAST);
+		fexpr->location = location;
+
+		return (Node *) fexpr;
+	}
+
+	/* try to coerce expression to the output type */
+	res = coerce_to_target_type(pstate, expr, exprtype,
+								returning->typid, returning->typmod,
+								/* XXX throwing errors when casting to char(N) */
+								COERCION_EXPLICIT,
+								COERCE_INTERNAL_CAST,
+								location);
+
+	if (!res && report_error)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast type %s to %s",
+						format_type_be(exprtype),
+						format_type_be(returning->typid)),
+				 parser_coercion_errposition(pstate, location, expr)));
+
+	return res;
+}
+
+static JsonCtorOpts *
+makeJsonCtorOpts(const JsonReturning *returning, bool unique,
+				 bool absent_on_null)
+{
+	JsonCtorOpts *opts = makeNode(JsonCtorOpts);
+
+	opts->returning  = *returning;
+	opts->unique = unique;
+	opts->absent_on_null = absent_on_null;
+
+	return opts;
+}
+
+/*
+ * Transform JSON_OBJECT() constructor.
+ *
+ * JSON_OBJECT() is transformed into json[b]_build_object[_ext]() call
+ * depending on the output JSON format. The first two arguments of
+ * json[b]_build_object_ext() are absent_on_null and check_key_uniqueness.
+ *
+ * Then function call result is coerced to the target type.
+ */
+static Node *
+transformJsonObjectCtor(ParseState *pstate, JsonObjectCtor *ctor)
+{
+	JsonReturning returning;
+	FuncExpr   *fexpr;
+	List	   *args = NIL;
+	Oid			funcid;
+	Oid			funcrettype;
+
+	/* transform key-value pairs, if any */
+	if (ctor->exprs)
+	{
+		ListCell   *lc;
+
+		/* append the first two arguments */
+		args = lappend(args, makeBoolConst(ctor->absent_on_null, false));
+		args = lappend(args, makeBoolConst(ctor->unique, false));
+
+		/* transform and append key-value arguments */
+		foreach(lc, ctor->exprs)
+		{
+			JsonKeyValue *kv = castNode(JsonKeyValue, lfirst(lc));
+			Node	   *key = transformExprRecurse(pstate, (Node *) kv->key);
+			Node	   *val = transformJsonValueExprDefault(pstate, kv->value);
+
+			args = lappend(args, key);
+			args = lappend(args, val);
+		}
+	}
+
+	transformJsonOutput(pstate, ctor->output, true, &returning);
+
+	if (returning.format.type == JS_FORMAT_JSONB)
+	{
+		funcid = args ? F_JSONB_BUILD_OBJECT_EXT : F_JSONB_BUILD_OBJECT_NOARGS;
+		funcrettype = JSONBOID;
+	}
+	else
+	{
+		funcid = args ? F_JSON_BUILD_OBJECT_EXT : F_JSON_BUILD_OBJECT_NOARGS;
+		funcrettype = JSONOID;
+	}
+
+	fexpr = makeFuncExpr(funcid, funcrettype, args,
+						 InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+	fexpr->location = ctor->location;
+	fexpr->funcformat2 = FUNCFMT_JSON_OBJECT;
+	fexpr->funcformatopts = (Node *) makeJsonCtorOpts(&returning,
+													  ctor->unique,
+													  ctor->absent_on_null);
+
+	return coerceJsonFuncExpr(pstate, (Node *) fexpr, &returning, true);
+}
+
+/*
+ * Transform JSON_ARRAY(query [FORMAT] [RETURNING] [ON NULL]) into
+ *  (SELECT  JSON_ARRAYAGG(a  [FORMAT] [RETURNING] [ON NULL]) FROM (query) q(a))
+ */
+static Node *
+transformJsonArrayQueryCtor(ParseState *pstate, JsonArrayQueryCtor *ctor)
+{
+	SubLink	   *sublink = makeNode(SubLink);
+	SelectStmt *select = makeNode(SelectStmt);
+	RangeSubselect *range = makeNode(RangeSubselect);
+	Alias	   *alias = makeNode(Alias);
+	ResTarget  *target = makeNode(ResTarget);
+	JsonArrayAgg *agg = makeNode(JsonArrayAgg);
+	ColumnRef  *colref = makeNode(ColumnRef);
+	Query	   *query;
+	ParseState *qpstate;
+
+	/* Transform query only for counting target list entries. */
+	qpstate = make_parsestate(pstate);
+
+	query = transformStmt(qpstate, ctor->query);
+
+	if (count_nonjunk_tlist_entries(query->targetList) != 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("subquery must return only one column"),
+				 parser_errposition(pstate, ctor->location)));
+
+	free_parsestate(qpstate);
+
+	colref->fields = list_make2(makeString(pstrdup("q")),
+								makeString(pstrdup("a")));
+	colref->location = ctor->location;
+
+	agg->arg = makeJsonValueExpr((Expr *) colref, ctor->format);
+	agg->ctor.agg_order = NIL;
+	agg->ctor.output = ctor->output;
+	agg->absent_on_null = ctor->absent_on_null;
+	agg->ctor.location = ctor->location;
+
+	target->name = NULL;
+	target->indirection = NIL;
+	target->val = (Node *) agg;
+	target->location = ctor->location;
+
+	alias->aliasname = pstrdup("q");
+	alias->colnames = list_make1(makeString(pstrdup("a")));
+
+	range->lateral = false;
+	range->subquery = ctor->query;
+	range->alias = alias;
+
+	select->targetList = list_make1(target);
+	select->fromClause = list_make1(range);
+
+	sublink->subLinkType = EXPR_SUBLINK;
+	sublink->subLinkId = 0;
+	sublink->testexpr = NULL;
+	sublink->operName = NIL;
+	sublink->subselect = (Node *) select;
+	sublink->location = ctor->location;
+
+	return transformExprRecurse(pstate, (Node *) sublink);
+}
+
+/*
+ * Common code for JSON_OBJECTAGG and JSON_ARRAYAGG transformation.
+ */
+static Node *
+transformJsonAggCtor(ParseState *pstate, JsonAggCtor *agg_ctor,
+					 JsonReturning *returning, List *args, Oid aggfnoid,
+					 Oid aggtype, FuncFormat format, JsonCtorOpts *formatopts)
+{
+	Node	   *node;
+	Expr	   *aggfilter = agg_ctor->agg_filter ? (Expr *)
+		transformWhereClause(pstate, agg_ctor->agg_filter,
+							 EXPR_KIND_FILTER, "FILTER") : NULL;
+
+	if (agg_ctor->over)
+	{
+		/* window function */
+		WindowFunc *wfunc = makeNode(WindowFunc);
+
+		wfunc->winfnoid = aggfnoid;
+		wfunc->wintype = aggtype;
+		/* wincollid and inputcollid will be set by parse_collate.c */
+		wfunc->args = args;
+		/* winref will be set by transformWindowFuncCall */
+		wfunc->winstar = false;
+		wfunc->winagg = true;
+		wfunc->aggfilter = aggfilter;
+		wfunc->winformat = format;
+		wfunc->winformatopts = (Node *) formatopts;
+		wfunc->location = agg_ctor->location;
+
+		/*
+		 * ordered aggs not allowed in windows yet
+		 */
+		if (agg_ctor->agg_order != NIL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("aggregate ORDER BY is not implemented for window functions"),
+					 parser_errposition(pstate, agg_ctor->location)));
+
+		/* parse_agg.c does additional window-func-specific processing */
+		transformWindowFuncCall(pstate, wfunc, agg_ctor->over);
+
+		node = (Node *) wfunc;
+	}
+	else
+	{
+		Aggref	   *aggref = makeNode(Aggref);
+
+		aggref->aggfnoid = aggfnoid;
+		aggref->aggtype = aggtype;
+
+		/* aggcollid and inputcollid will be set by parse_collate.c */
+		aggref->aggtranstype = InvalidOid;		/* will be set by planner */
+		/* aggargtypes will be set by transformAggregateCall */
+		/* aggdirectargs and args will be set by transformAggregateCall */
+		/* aggorder and aggdistinct will be set by transformAggregateCall */
+		aggref->aggfilter = aggfilter;
+		aggref->aggstar = false;
+		aggref->aggvariadic = false;
+		aggref->aggkind = AGGKIND_NORMAL;
+		/* agglevelsup will be set by transformAggregateCall */
+		aggref->aggsplit = AGGSPLIT_SIMPLE;		/* planner might change this */
+		aggref->aggformat = format;
+		aggref->aggformatopts = (Node *) formatopts;
+		aggref->location = agg_ctor->location;
+
+		transformAggregateCall(pstate, aggref, args, agg_ctor->agg_order, false);
+
+		node = (Node *) aggref;
+	}
+
+	return coerceJsonFuncExpr(pstate, node, returning, true);
+}
+
+/*
+ * Transform JSON_OBJECTAGG() aggregate function.
+ *
+ * JSON_OBJECTAGG() is transformed into
+ * json[b]_objectagg(key, value, absent_on_null, check_unique) call depending on
+ * the output JSON format.  Then the function call result is coerced to the
+ * target output type.
+ */
+static Node *
+transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg)
+{
+	JsonReturning returning;
+	Node	   *key;
+	Node	   *val;
+	List	   *args;
+	Oid			aggfnoid;
+	Oid			aggtype;
+
+	transformJsonOutput(pstate, agg->ctor.output, true, &returning);
+
+	key = transformExprRecurse(pstate, (Node *) agg->arg->key);
+	val = transformJsonValueExprDefault(pstate, agg->arg->value);
+
+	args = list_make4(key,
+					  val,
+					  makeBoolConst(agg->absent_on_null, false),
+					  makeBoolConst(agg->unique, false));
+
+	if (returning.format.type == JS_FORMAT_JSONB)
+	{
+		aggfnoid = F_JSONB_OBJECTAGG;
+		aggtype = JSONBOID;
+	}
+	else
+	{
+		aggfnoid = F_JSON_OBJECTAGG;
+		aggtype = JSONOID;
+	}
+
+	return transformJsonAggCtor(pstate, &agg->ctor, &returning, args, aggfnoid,
+								aggtype, FUNCFMT_JSON_OBJECTAGG,
+								makeJsonCtorOpts(&returning,
+												 agg->unique,
+												 agg->absent_on_null));
+}
+
+/*
+ * Transform JSON_ARRAYAGG() aggregate function.
+ *
+ * JSON_ARRAYAGG() is transformed into json[b]_agg[_strict]() call depending
+ * on the output JSON format and absent_on_null.  Then the function call result
+ * is coerced to the target output type.
+ */
+static Node *
+transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg)
+{
+	JsonReturning returning;
+	Node	   *arg;
+	Oid			aggfnoid;
+	Oid			aggtype;
+
+	transformJsonOutput(pstate, agg->ctor.output, true, &returning);
+
+	arg = transformJsonValueExprDefault(pstate, agg->arg);
+
+	if (returning.format.type == JS_FORMAT_JSONB)
+	{
+		aggfnoid = agg->absent_on_null ? F_JSONB_AGG_STRICT : F_JSONB_AGG;
+		aggtype = JSONBOID;
+	}
+	else
+	{
+		aggfnoid = agg->absent_on_null ? F_JSON_AGG_STRICT : F_JSON_AGG;
+		aggtype = JSONOID;
+	}
+
+	return transformJsonAggCtor(pstate, &agg->ctor, &returning, list_make1(arg),
+								aggfnoid, aggtype, FUNCFMT_JSON_ARRAYAGG,
+								makeJsonCtorOpts(&returning,
+												 false, agg->absent_on_null));
+}
+
+/*
+ * Transform JSON_ARRAY() constructor.
+ *
+ * JSON_ARRAY() is transformed into json[b]_build_array[_ext]() call
+ * depending on the output JSON format. The first argument of
+ * json[b]_build_array_ext() is absent_on_null.
+ *
+ * Then function call result is coerced to the target type.
+ */
+static Node *
+transformJsonArrayCtor(ParseState *pstate, JsonArrayCtor *ctor)
+{
+	JsonReturning returning;
+	FuncExpr   *fexpr;
+	List	   *args = NIL;
+	Oid			funcid;
+	Oid			funcrettype;
+
+	/* transform element expressions, if any */
+	if (ctor->exprs)
+	{
+		ListCell   *lc;
+
+		/* append the first absent_on_null argument */
+		args = lappend(args, makeBoolConst(ctor->absent_on_null, false));
+
+		/* transform and append element arguments */
+		foreach(lc, ctor->exprs)
+		{
+			JsonValueExpr *jsval = castNode(JsonValueExpr, lfirst(lc));
+			Node	   *val = transformJsonValueExprDefault(pstate, jsval);
+
+			args = lappend(args, val);
+		}
+	}
+
+	transformJsonOutput(pstate, ctor->output, true, &returning);
+
+	if (returning.format.type == JS_FORMAT_JSONB)
+	{
+		funcid = args ? F_JSONB_BUILD_ARRAY_EXT : F_JSONB_BUILD_ARRAY_NOARGS;
+		funcrettype = JSONBOID;
+	}
+	else
+	{
+		funcid = args ? F_JSON_BUILD_ARRAY_EXT : F_JSON_BUILD_ARRAY_NOARGS;
+		funcrettype = JSONOID;
+	}
+
+	fexpr = makeFuncExpr(funcid, funcrettype, args,
+						 InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+	fexpr->location = ctor->location;
+	fexpr->funcformat2 = FUNCFMT_JSON_ARRAY;
+	fexpr->funcformatopts = (Node *) makeJsonCtorOpts(&returning, false,
+													  ctor->absent_on_null);
+
+	return coerceJsonFuncExpr(pstate, (Node *) fexpr, &returning, true);
+}
+
+static const char *
+JsonValueTypeStrings[] =
+{
+	"any",
+	"object",
+	"array",
+	"scalar",
+};
+
+static Const *
+makeJsonValueTypeConst(JsonValueType type)
+{
+	return makeConst(TEXTOID, -1, InvalidOid, -1,
+					 PointerGetDatum(cstring_to_text(
+											JsonValueTypeStrings[(int) type])),
+					 false, false);
+}
+
+/*
+ * Transform IS JSON predicate into
+ * json[b]_is_valid(json, value_type [, check_key_uniqueness]) call.
+ */
+static Node *
+transformJsonIsPredicate(ParseState *pstate, JsonIsPredicate *pred)
+{
+	Node	   *expr = transformExprRecurse(pstate, pred->expr);
+	Oid			exprtype = exprType(expr);
+	FuncExpr   *fexpr;
+	JsonIsPredicateOpts *opts;
+
+	/* prepare input document */
+	if (exprtype == BYTEAOID)
+	{
+		expr = makeJsonByteaToTextConversion(expr, &pred->format,
+											 exprLocation(expr));
+		exprtype = TEXTOID;
+	}
+	else
+	{
+		char		typcategory;
+		bool		typispreferred;
+
+		get_type_category_preferred(exprtype, &typcategory, &typispreferred);
+
+		if (exprtype == UNKNOWNOID || typcategory == TYPCATEGORY_STRING)
+		{
+			expr = coerce_to_target_type(pstate, (Node *) expr, exprtype,
+										 TEXTOID, -1,
+										 COERCION_IMPLICIT,
+										 COERCE_IMPLICIT_CAST, -1);
+			exprtype = TEXTOID;
+		}
+
+		if (pred->format.encoding != JS_ENC_DEFAULT)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 parser_errposition(pstate, pred->format.location),
+					 errmsg("cannot use JSON FORMAT ENCODING clause for non-bytea input types")));
+	}
+
+	expr = (Node *) makeJsonValueExpr((Expr *) expr, pred->format);
+
+	/* make resulting expression */
+	if (exprtype == TEXTOID || exprtype == JSONOID)
+	{
+		fexpr = makeFuncExpr(F_JSON_IS_VALID, BOOLOID,
+							 list_make3(expr,
+										makeJsonValueTypeConst(pred->vtype),
+										makeBoolConst(pred->unique_keys, false)),
+							 InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+
+		fexpr->location = pred->location;
+	}
+	else if (exprtype == JSONBOID)
+	{
+		/* XXX the following expressions also can be used here:
+		 * jsonb_type(jsonb) = 'type' (for object and array checks)
+		 * CASE jsonb_type(jsonb) WHEN ... END (for scalars checks)
+		 */
+		fexpr = makeFuncExpr(F_JSONB_IS_VALID, BOOLOID,
+							 list_make2(expr,
+										makeJsonValueTypeConst(pred->vtype)),
+							 InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+
+		fexpr->location = pred->location;
+	}
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("cannot use type %s in IS JSON predicate",
+						 format_type_be(exprtype))));
+		return NULL;
+	}
+
+	opts = makeNode(JsonIsPredicateOpts);
+	opts->unique_keys = pred->unique_keys;
+	opts->value_type = pred->vtype;
+
+	fexpr->funcformat2 = FUNCFMT_IS_JSON;
+	fexpr->funcformatopts = (Node *) opts;
+
+	return (Node *) fexpr;
+}
+
+/*
+ * Transform a JSON PASSING clause.
+ */
+static void
+transformJsonPassingArgs(ParseState *pstate, JsonFormatType format, List *args,
+						 JsonPassing *passing)
+{
+	ListCell   *lc;
+
+	passing->values = NIL;
+	passing->names = NIL;
+
+	foreach(lc, args)
+	{
+		JsonArgument *arg = castNode(JsonArgument, lfirst(lc));
+		Node	   *expr = transformJsonValueExprExt(pstate, arg->val,
+													 format, true, NULL);
+
+		assign_expr_collations(pstate, expr);
+
+		passing->values = lappend(passing->values, expr);
+		passing->names = lappend(passing->names, makeString(arg->name));
+	}
+}
+
+/*
+ * Transform a JSON BEHAVIOR clause.
+ */
+static JsonBehavior
+transformJsonBehavior(ParseState *pstate, JsonBehavior *behavior,
+					  JsonBehaviorType default_behavior)
+{
+	JsonBehavior b;
+
+	b.btype = behavior ? behavior->btype : default_behavior;
+	b.default_expr = b.btype != JSON_BEHAVIOR_DEFAULT ? NULL :
+		transformExprRecurse(pstate, behavior->default_expr);
+
+	return b;
+}
+
+/*
+ * Common code for JSON_VALUE, JSON_QUERY, JSON_EXISTS transformation
+ * into a JsonExpr node.
+ */
+static JsonExpr *
+transformJsonExprCommon(ParseState *pstate, JsonFuncExpr *func)
+{
+	JsonExpr   *jsexpr = makeNode(JsonExpr);
+	Node	   *pathspec;
+	JsonFormatType format;
+
+	if (func->common->pathname)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("JSON_TABLE path name is not allowed here"),
+				 parser_errposition(pstate, func->location)));
+
+	jsexpr->location = func->location;
+	jsexpr->op = func->op;
+	jsexpr->formatted_expr = transformJsonValueExprExt(pstate,
+													   func->common->expr,
+													   JS_FORMAT_JSON,
+													   false,
+													   &jsexpr->raw_expr);
+
+	assign_expr_collations(pstate, jsexpr->formatted_expr);
+
+	/* format is determined by context item type */
+	format = exprType(jsexpr->formatted_expr) == JSONBOID ?
+		JS_FORMAT_JSONB : JS_FORMAT_JSON;
+
+	if (jsexpr->formatted_expr == jsexpr->raw_expr)
+		jsexpr->formatted_expr = NULL;
+
+	jsexpr->result_coercion = NULL;
+	jsexpr->omit_quotes = false;
+
+	jsexpr->format = func->common->expr->format;
+
+	pathspec = transformExprRecurse(pstate, func->common->pathspec);
+
+	jsexpr->path_spec =
+		coerce_to_target_type(pstate, pathspec, exprType(pathspec),
+							  JSONPATHOID, -1,
+							  COERCION_EXPLICIT, COERCE_IMPLICIT_CAST,
+							  exprLocation(pathspec));
+	if (!jsexpr->path_spec)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("JSON path expression must be type %s, not type %s",
+						"jsonpath", format_type_be(exprType(pathspec))),
+				 parser_errposition(pstate, exprLocation(pathspec))));
+
+	/* transform and coerce to json[b] passing arguments */
+	transformJsonPassingArgs(pstate, format, func->common->passing,
+							 &jsexpr->passing);
+
+	if (func->op != IS_JSON_EXISTS)
+		jsexpr->on_empty = transformJsonBehavior(pstate, func->on_empty,
+												 JSON_BEHAVIOR_NULL);
+
+	jsexpr->on_error = transformJsonBehavior(pstate, func->on_error,
+											 func->op == IS_JSON_EXISTS ?
+											 JSON_BEHAVIOR_FALSE :
+											 JSON_BEHAVIOR_NULL);
+
+	return jsexpr;
+}
+
+/*
+ * Assign default JSON returning type from the specified format or from
+ * the context item type.
+ */
+static void
+assignDefaultJsonReturningType(Node *context_item, JsonFormat *context_format,
+							   JsonReturning *ret)
+{
+	bool		is_jsonb;
+
+	ret->format = *context_format;
+
+	if (ret->format.type == JS_FORMAT_DEFAULT)
+		is_jsonb = exprType(context_item) == JSONBOID;
+	else
+		is_jsonb = ret->format.type == JS_FORMAT_JSONB;
+
+	ret->typid = is_jsonb ? JSONBOID : JSONOID;
+	ret->typmod = -1;
+}
+
+/*
+ * Try to coerce expression to the output type or
+ * use json_populate_type() for composite, array and domain types or
+ * use coercion via I/O.
+ */
+static JsonCoercion *
+coerceJsonExpr(ParseState *pstate, Node *expr, JsonReturning *returning)
+{
+	char		typtype;
+	JsonCoercion *coercion = makeNode(JsonCoercion);
+
+	coercion->expr = coerceJsonFuncExpr(pstate, expr, returning, false);
+
+	if (coercion->expr)
+	{
+		if (coercion->expr == expr)
+			coercion->expr = NULL;
+
+		return coercion;
+	}
+
+	typtype = get_typtype(returning->typid);
+
+	if (returning->typid == RECORDOID ||
+		typtype == TYPTYPE_COMPOSITE ||
+		typtype == TYPTYPE_DOMAIN ||
+		type_is_array(returning->typid))
+		coercion->via_populate = true;
+	else
+		coercion->via_io = true;
+
+	return coercion;
+}
+
+/*
+ * Transform a JSON output clause of JSON_VALUE, JSON_QUERY, JSON_EXISTS.
+ */
+static void
+transformJsonFuncExprOutput(ParseState *pstate,	JsonFuncExpr *func,
+							JsonExpr *jsexpr)
+{
+	Node	   *expr = jsexpr->formatted_expr ?
+					   jsexpr->formatted_expr : jsexpr->raw_expr;
+
+	transformJsonOutput(pstate, func->output, false, &jsexpr->returning);
+
+	/* JSON_VALUE returns text by default */
+	if (func->op == IS_JSON_VALUE && !OidIsValid(jsexpr->returning.typid))
+	{
+		jsexpr->returning.typid = TEXTOID;
+		jsexpr->returning.typmod = -1;
+	}
+
+	if (OidIsValid(jsexpr->returning.typid))
+	{
+		JsonReturning ret;
+
+		if (func->op == IS_JSON_VALUE &&
+			jsexpr->returning.typid != JSONOID &&
+			jsexpr->returning.typid != JSONBOID)
+		{
+			/* Forced coercion via I/O for JSON_VALUE for non-JSON types */
+			jsexpr->result_coercion = makeNode(JsonCoercion);
+			jsexpr->result_coercion->expr = NULL;
+			jsexpr->result_coercion->via_io = true;
+			return;
+		}
+
+		assignDefaultJsonReturningType(jsexpr->raw_expr, &jsexpr->format, &ret);
+
+		if (ret.typid != jsexpr->returning.typid ||
+			ret.typmod != jsexpr->returning.typmod)
+		{
+			Node	   *placeholder = makeCaseTestExpr(expr);
+
+			Assert(((CaseTestExpr *) placeholder)->typeId == ret.typid);
+			Assert(((CaseTestExpr *) placeholder)->typeMod == ret.typmod);
+
+			jsexpr->result_coercion = coerceJsonExpr(pstate, placeholder,
+													 &jsexpr->returning);
+		}
+	}
+	else
+		assignDefaultJsonReturningType(jsexpr->raw_expr, &jsexpr->format,
+									   &jsexpr->returning);
+}
+
+/*
+ * Coerce a expression in JSON DEFAULT behavior to the target output type.
+ */
+static Node *
+coerceDefaultJsonExpr(ParseState *pstate, JsonExpr *jsexpr, Node *defexpr)
+{
+	int			location;
+	Oid			exprtype;
+
+	if (!defexpr)
+		return NULL;
+
+	exprtype = exprType(defexpr);
+	location = exprLocation(defexpr);
+
+	if (location < 0)
+		location = jsexpr->location;
+
+	defexpr = coerce_to_target_type(pstate,
+									defexpr,
+									exprtype,
+									jsexpr->returning.typid,
+									jsexpr->returning.typmod,
+									COERCION_EXPLICIT,
+									COERCE_INTERNAL_CAST,
+									location);
+
+	if (!defexpr)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast DEFAULT expression type %s to %s",
+						format_type_be(exprtype),
+						format_type_be(jsexpr->returning.typid)),
+				 parser_errposition(pstate, location)));
+
+	return defexpr;
+}
+
+/*
+ * Initialize SQL/JSON item coercion from the SQL type "typid" to the target
+ * "returning" type.
+ */
+static JsonCoercion *
+initJsonItemCoercion(ParseState *pstate, Oid typid, JsonReturning *returning)
+{
+	Node	   *expr;
+
+	if (typid == UNKNOWNOID)
+	{
+		expr = (Node *) makeNullConst(UNKNOWNOID, -1, InvalidOid);
+	}
+	else
+	{
+		CaseTestExpr *placeholder = makeNode(CaseTestExpr);
+
+		placeholder->typeId = typid;
+		placeholder->typeMod = -1;
+		placeholder->collation = InvalidOid;
+
+		expr = (Node *) placeholder;
+	}
+
+	return coerceJsonExpr(pstate, expr, returning);
+}
+
+static void
+initJsonItemCoercions(ParseState *pstate, JsonItemCoercions *coercions,
+					  JsonReturning *returning, Oid contextItemTypeId)
+{
+	struct
+	{
+		JsonCoercion **coercion;
+		Oid			typid;
+	}		   *p,
+				coercionTypids[] =
+				{
+					{ &coercions->null, UNKNOWNOID },
+					{ &coercions->string, TEXTOID },
+					{ &coercions->numeric, NUMERICOID },
+					{ &coercions->boolean, BOOLOID },
+					{ &coercions->date, DATEOID },
+					{ &coercions->time, TIMEOID },
+					{ &coercions->timetz, TIMETZOID },
+					{ &coercions->timestamp, TIMESTAMPOID },
+					{ &coercions->timestamptz, TIMESTAMPTZOID },
+					{ &coercions->composite, contextItemTypeId },
+					{ NULL, InvalidOid }
+				};
+
+	for (p = coercionTypids; p->coercion; p++)
+		*p->coercion = initJsonItemCoercion(pstate, p->typid, returning);
+}
+
+/*
+ * Transform JSON_VALUE, JSON_QUERY, JSON_EXISTS functions into a JsonExpr node.
+ */
+static Node *
+transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
+{
+	JsonExpr   *jsexpr = transformJsonExprCommon(pstate, func);
+	Node	   *contextItemExpr =
+		jsexpr->formatted_expr ? jsexpr->formatted_expr : jsexpr->raw_expr;
+	const char *func_name = NULL;
+
+	switch (func->op)
+	{
+		case IS_JSON_VALUE:
+			func_name = "JSON_VALUE";
+
+			transformJsonFuncExprOutput(pstate, func, jsexpr);
+
+			jsexpr->returning.format.type = JS_FORMAT_DEFAULT;
+			jsexpr->returning.format.encoding = JS_ENC_DEFAULT;
+
+			jsexpr->on_empty.default_expr =
+					coerceDefaultJsonExpr(pstate, jsexpr,
+										  jsexpr->on_empty.default_expr);
+
+			jsexpr->on_error.default_expr =
+					coerceDefaultJsonExpr(pstate, jsexpr,
+										  jsexpr->on_error.default_expr);
+
+			jsexpr->coercions = makeNode(JsonItemCoercions);
+			initJsonItemCoercions(pstate, jsexpr->coercions, &jsexpr->returning,
+								  exprType(contextItemExpr));
+
+			break;
+
+		case IS_JSON_QUERY:
+			func_name = "JSON_QUERY";
+
+			transformJsonFuncExprOutput(pstate, func, jsexpr);
+
+			jsexpr->wrapper = func->wrapper;
+			jsexpr->omit_quotes = func->omit_quotes;
+
+			break;
+
+		case IS_JSON_EXISTS:
+			func_name = "JSON_EXISTS";
+
+			jsexpr->returning.format.type = JS_FORMAT_DEFAULT;
+			jsexpr->returning.format.encoding = JS_ENC_DEFAULT;
+			jsexpr->returning.format.location = -1;
+			jsexpr->returning.typid = BOOLOID;
+			jsexpr->returning.typmod = -1;
+
+			break;
+	}
+
+	if (exprType(contextItemExpr) != JSONBOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("%s() is not yet implemented for json type", func_name),
+				 parser_errposition(pstate, func->location)));
+
+	return (Node *) jsexpr;
+}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index ea209cd..e5a71c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1917,6 +1917,34 @@ FigureColnameInternal(Node *node, char **name)
 		case T_XmlSerialize:
 			*name = "xmlserialize";
 			return 2;
+		case T_JsonObjectCtor:
+			*name = "json_object";
+			return 2;
+		case T_JsonArrayCtor:
+		case T_JsonArrayQueryCtor:
+			*name = "json_array";
+			return 2;
+		case T_JsonObjectAgg:
+			*name = "json_objectagg";
+			return 2;
+		case T_JsonArrayAgg:
+			*name = "json_arrayagg";
+			return 2;
+		case T_JsonFuncExpr:
+			/* make SQL/JSON functions act like a regular function */
+			switch (((JsonFuncExpr *) node)->op)
+			{
+				case IS_JSON_QUERY:
+					*name = "json_query";
+					return 2;
+				case IS_JSON_VALUE:
+					*name = "json_value";
+					return 2;
+				case IS_JSON_EXISTS:
+					*name = "json_exists";
+					return 2;
+			}
+			break;
 		default:
 			break;
 	}
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index db30483..3be9d6c 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -24,7 +24,6 @@
 #include "parser/gramparse.h"
 #include "parser/parser.h"
 
-
 /*
  * raw_parser
  *		Given a query in string form, do lexical and grammatical analysis.
@@ -117,6 +116,9 @@ base_yylex(YYSTYPE *lvalp, YYLTYPE *llocp, core_yyscan_t yyscanner)
 		case WITH:
 			cur_token_length = 4;
 			break;
+		case WITHOUT:
+			cur_token_length = 7;
+			break;
 		default:
 			return cur_token;
 	}
@@ -188,8 +190,22 @@ base_yylex(YYSTYPE *lvalp, YYLTYPE *llocp, core_yyscan_t yyscanner)
 				case ORDINALITY:
 					cur_token = WITH_LA;
 					break;
+				case UNIQUE:
+					cur_token = WITH_LA_UNIQUE;
+					break;
 			}
 			break;
+
+		case WITHOUT:
+			/* Replace WITHOUT by WITHOUT_LA if it's followed by TIME */
+			switch (next_token)
+			{
+				case TIME:
+					cur_token = WITHOUT_LA;
+					break;
+			}
+			break;
+
 	}
 
 	return cur_token;
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index b19d7b1..4f9da97 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -13,6 +13,7 @@
  */
 #include "postgres.h"
 
+#include "access/hash.h"
 #include "access/htup_details.h"
 #include "access/transam.h"
 #include "catalog/pg_type.h"
@@ -66,6 +67,23 @@ typedef enum					/* type categories for datum_to_json */
 	JSONTYPE_OTHER				/* all else */
 } JsonTypeCategory;
 
+/* Context for key uniqueness check */
+typedef struct JsonUniqueCheckContext
+{
+	struct JsonKeyInfo
+	{
+		int			offset;				/* key offset:
+										 *   in result if positive,
+										 *   in skipped_keys if negative */
+		int			length;				/* key length */
+	}		   *keys;					/* key info array */
+	int			nkeys;					/* number of processed keys */
+	int			nallocated;				/* number of allocated keys in array */
+	StringInfo	result;					/* resulting json */
+	StringInfoData skipped_keys;		/* skipped keys with NULL values */
+	MemoryContext mcxt;					/* context for saving skipped keys */
+} JsonUniqueCheckContext;
+
 typedef struct JsonAggState
 {
 	StringInfo	str;
@@ -73,8 +91,23 @@ typedef struct JsonAggState
 	Oid			key_output_func;
 	JsonTypeCategory val_category;
 	Oid			val_output_func;
+	JsonUniqueCheckContext unique_check;
 } JsonAggState;
 
+/* Element of object stack for key uniqueness check */
+typedef struct JsonObjectFields
+{
+	struct JsonObjectFields *parent;
+	HTAB	   *fields;
+} JsonObjectFields;
+
+/* State for key uniqueness check */
+typedef struct JsonUniqueState
+{
+	JsonLexContext *lex;
+	JsonObjectFields *stack;
+} JsonUniqueState;
+
 static inline void json_lex(JsonLexContext *lex);
 static inline void json_lex_string(JsonLexContext *lex);
 static inline void json_lex_number(JsonLexContext *lex, char *s,
@@ -1962,8 +1995,8 @@ to_json(PG_FUNCTION_ARGS)
  *
  * aggregate input column as a json array value.
  */
-Datum
-json_agg_transfn(PG_FUNCTION_ARGS)
+static Datum
+json_agg_transfn_worker(FunctionCallInfo fcinfo, bool absent_on_null)
 {
 	MemoryContext aggcontext,
 				oldcontext;
@@ -2003,9 +2036,14 @@ json_agg_transfn(PG_FUNCTION_ARGS)
 	else
 	{
 		state = (JsonAggState *) PG_GETARG_POINTER(0);
-		appendStringInfoString(state->str, ", ");
 	}
 
+	if (absent_on_null && PG_ARGISNULL(1))
+		PG_RETURN_POINTER(state);
+
+	if (state->str->len > 1)
+		appendStringInfoString(state->str, ", ");
+
 	/* fast path for NULLs */
 	if (PG_ARGISNULL(1))
 	{
@@ -2017,7 +2055,7 @@ json_agg_transfn(PG_FUNCTION_ARGS)
 	val = PG_GETARG_DATUM(1);
 
 	/* add some whitespace if structured type and not first item */
-	if (!PG_ARGISNULL(0) &&
+	if (!PG_ARGISNULL(0) && state->str->len > 1 &&
 		(state->val_category == JSONTYPE_ARRAY ||
 		 state->val_category == JSONTYPE_COMPOSITE))
 	{
@@ -2035,6 +2073,25 @@ json_agg_transfn(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state);
 }
 
+
+/*
+ * json_agg aggregate function
+ */
+Datum
+json_agg_transfn(PG_FUNCTION_ARGS)
+{
+	return json_agg_transfn_worker(fcinfo, false);
+}
+
+/*
+ * json_agg_strict aggregate function
+ */
+Datum
+json_agg_strict_transfn(PG_FUNCTION_ARGS)
+{
+	return json_agg_transfn_worker(fcinfo, true);
+}
+
 /*
  * json_agg final function
  */
@@ -2058,18 +2115,115 @@ json_agg_finalfn(PG_FUNCTION_ARGS)
 	PG_RETURN_TEXT_P(catenate_stringinfo_string(state->str, "]"));
 }
 
+static inline void
+json_unique_check_init(JsonUniqueCheckContext *cxt,
+					   StringInfo result, int nkeys)
+{
+	cxt->mcxt = CurrentMemoryContext;
+	cxt->nkeys = 0;
+	cxt->nallocated = nkeys ? nkeys : 16;
+	cxt->keys = palloc(sizeof(*cxt->keys) * cxt->nallocated);
+	cxt->result = result;
+	cxt->skipped_keys.data = NULL;
+}
+
+static inline void
+json_unique_check_free(JsonUniqueCheckContext *cxt)
+{
+	if (cxt->keys)
+		pfree(cxt->keys);
+
+	if (cxt->skipped_keys.data)
+		pfree(cxt->skipped_keys.data);
+}
+
+/* On-demand initialization of skipped_keys StringInfo structure */
+static inline StringInfo
+json_unique_check_get_skipped_keys(JsonUniqueCheckContext *cxt)
+{
+	StringInfo	out = &cxt->skipped_keys;
+
+	if (!out->data)
+	{
+		MemoryContext oldcxt = MemoryContextSwitchTo(cxt->mcxt);
+		initStringInfo(out);
+		MemoryContextSwitchTo(oldcxt);
+	}
+
+	return out;
+}
+
+/*
+ * Save current key offset (key is not yet appended) to the key list, key
+ * length is saved later in json_unique_check_key() when the key is appended.
+ */
+static inline void
+json_unique_check_save_key_offset(JsonUniqueCheckContext *cxt, StringInfo out)
+{
+	if (cxt->nkeys >= cxt->nallocated)
+	{
+		cxt->nallocated *= 2;
+		cxt->keys = repalloc(cxt->keys, sizeof(*cxt->keys) * cxt->nallocated);
+	}
+
+	cxt->keys[cxt->nkeys++].offset = out->len;
+}
+
+/*
+ * Check uniqueness of key already appended to 'out' StringInfo.
+ */
+static inline void
+json_unique_check_key(JsonUniqueCheckContext *cxt, StringInfo out)
+{
+	struct JsonKeyInfo *keys = cxt->keys;
+	int			curr = cxt->nkeys - 1;
+	int			offset = keys[curr].offset;
+	int			length = out->len - offset;
+	char	   *curr_key = &out->data[offset];
+	int			i;
+
+	keys[curr].length = length; /* save current key length */
+
+	if (out == &cxt->skipped_keys)
+		/* invert offset for skipped keys for their recognition */
+		keys[curr].offset = -keys[curr].offset;
+
+	/* check collisions with previous keys */
+	for (i = 0; i < curr; i++)
+	{
+		char	   *prev_key;
+
+		if (cxt->keys[i].length != length)
+			continue;
+
+		offset = cxt->keys[i].offset;
+
+		prev_key = offset > 0
+				? &cxt->result->data[offset]
+				: &cxt->skipped_keys.data[-offset];
+
+		if (!memcmp(curr_key, prev_key, length))
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_JSON_OBJECT_KEY_VALUE),
+					 errmsg("duplicate JSON key %s", curr_key)));
+	}
+}
+
 /*
  * json_object_agg transition function.
  *
  * aggregate two input columns as a single json object value.
  */
-Datum
-json_object_agg_transfn(PG_FUNCTION_ARGS)
+static Datum
+json_object_agg_transfn_worker(FunctionCallInfo fcinfo,
+							   bool absent_on_null, bool unique_keys)
 {
 	MemoryContext aggcontext,
 				oldcontext;
 	JsonAggState *state;
+	StringInfo	out;
 	Datum		arg;
+	bool		skip;
 
 	if (!AggCheckCallContext(fcinfo, &aggcontext))
 	{
@@ -2090,6 +2244,10 @@ json_object_agg_transfn(PG_FUNCTION_ARGS)
 		oldcontext = MemoryContextSwitchTo(aggcontext);
 		state = (JsonAggState *) palloc(sizeof(JsonAggState));
 		state->str = makeStringInfo();
+		if (unique_keys)
+			json_unique_check_init(&state->unique_check, state->str, 0);
+		else
+			memset(&state->unique_check, 0, sizeof(state->unique_check));
 		MemoryContextSwitchTo(oldcontext);
 
 		arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
@@ -2117,7 +2275,6 @@ json_object_agg_transfn(PG_FUNCTION_ARGS)
 	else
 	{
 		state = (JsonAggState *) PG_GETARG_POINTER(0);
-		appendStringInfoString(state->str, ", ");
 	}
 
 	/*
@@ -2133,11 +2290,41 @@ json_object_agg_transfn(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("field name must not be null")));
 
+	/* Skip null values if absent_on_null */
+	skip = absent_on_null && PG_ARGISNULL(2);
+
+	if (skip)
+	{
+		/* If key uniqueness check is needed we must save skipped keys */
+		if (!unique_keys)
+			PG_RETURN_POINTER(state);
+
+		out = json_unique_check_get_skipped_keys(&state->unique_check);
+	}
+	else
+	{
+		out = state->str;
+
+		if (out->len > 2)
+			appendStringInfoString(out, ", ");
+	}
+
 	arg = PG_GETARG_DATUM(1);
 
-	datum_to_json(arg, false, state->str, state->key_category,
+	if (unique_keys)
+		json_unique_check_save_key_offset(&state->unique_check, out);
+
+	datum_to_json(arg, false, out, state->key_category,
 				  state->key_output_func, true);
 
+	if (unique_keys)
+	{
+		json_unique_check_key(&state->unique_check, out);
+
+		if (skip)
+			PG_RETURN_POINTER(state);
+	}
+
 	appendStringInfoString(state->str, " : ");
 
 	if (PG_ARGISNULL(2))
@@ -2152,6 +2339,26 @@ json_object_agg_transfn(PG_FUNCTION_ARGS)
 }
 
 /*
+ * json_object_agg aggregate function
+ */
+Datum
+json_object_agg_transfn(PG_FUNCTION_ARGS)
+{
+	return json_object_agg_transfn_worker(fcinfo, false, false);
+}
+
+/*
+ * json_objectagg aggregate function
+ */
+Datum
+json_objectagg_transfn(PG_FUNCTION_ARGS)
+{
+	return json_object_agg_transfn_worker(fcinfo,
+										  PG_GETARG_BOOL(3),
+										  PG_GETARG_BOOL(4));
+}
+
+/*
  * json_object_agg final function.
  */
 Datum
@@ -2168,6 +2375,8 @@ json_object_agg_finalfn(PG_FUNCTION_ARGS)
 	if (state == NULL)
 		PG_RETURN_NULL();
 
+	json_unique_check_free(&state->unique_check);
+
 	/* Else return state with appropriate object terminator added */
 	PG_RETURN_TEXT_P(catenate_stringinfo_string(state->str, " }"));
 }
@@ -2192,11 +2401,9 @@ catenate_stringinfo_string(StringInfo buffer, const char *addon)
 	return result;
 }
 
-/*
- * SQL function json_build_object(variadic "any")
- */
-Datum
-json_build_object(PG_FUNCTION_ARGS)
+static Datum
+json_build_object_worker(FunctionCallInfo fcinfo, int first_vararg,
+						 bool absent_on_null, bool unique_keys)
 {
 	int			nargs = PG_NARGS();
 	int			i;
@@ -2205,9 +2412,11 @@ json_build_object(PG_FUNCTION_ARGS)
 	Datum	   *args;
 	bool	   *nulls;
 	Oid		   *types;
+	JsonUniqueCheckContext unique_check;
 
 	/* fetch argument values to build the object */
-	nargs = extract_variadic_args(fcinfo, 0, false, &args, &types, &nulls);
+	nargs = extract_variadic_args(fcinfo, first_vararg, false,
+								  &args, &types, &nulls);
 
 	if (nargs < 0)
 		PG_RETURN_NULL();
@@ -2222,19 +2431,53 @@ json_build_object(PG_FUNCTION_ARGS)
 
 	appendStringInfoChar(result, '{');
 
+	if (unique_keys)
+		json_unique_check_init(&unique_check, result, nargs / 2);
+
 	for (i = 0; i < nargs; i += 2)
 	{
-		appendStringInfoString(result, sep);
-		sep = ", ";
+		StringInfo	out;
+		bool		skip;
+
+		/* Skip null values if absent_on_null */
+		skip = absent_on_null && nulls[i + 1];
+
+		if (skip)
+		{
+			/* If key uniqueness check is needed we must save skipped keys */
+			if (!unique_keys)
+				continue;
+
+			out = json_unique_check_get_skipped_keys(&unique_check);
+		}
+		else
+		{
+			appendStringInfoString(result, sep);
+			sep = ", ";
+			out = result;
+		}
 
 		/* process key */
 		if (nulls[i])
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("argument %d cannot be null", i + 1),
+					 errmsg("argument %d cannot be null", first_vararg + i + 1),
 					 errhint("Object keys should be text.")));
 
-		add_json(args[i], false, result, types[i], true);
+		if (unique_keys)
+			/* save key offset before key appending */
+			json_unique_check_save_key_offset(&unique_check, out);
+
+		add_json(args[i], false, out, types[i], true);
+
+		if (unique_keys)
+		{
+			/* check key uniqueness after key appending */
+			json_unique_check_key(&unique_check, out);
+
+			if (skip)
+				continue;
+		}
 
 		appendStringInfoString(result, " : ");
 
@@ -2244,23 +2487,43 @@ json_build_object(PG_FUNCTION_ARGS)
 
 	appendStringInfoChar(result, '}');
 
+	if (unique_keys)
+		json_unique_check_free(&unique_check);
+
 	PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
 }
 
 /*
- * degenerate case of json_build_object where it gets 0 arguments.
+ * SQL function json_build_object(variadic "any")
  */
 Datum
-json_build_object_noargs(PG_FUNCTION_ARGS)
+json_build_object(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TEXT_P(cstring_to_text_with_len("{}", 2));
+	return json_build_object_worker(fcinfo, 0, false, false);
 }
 
 /*
- * SQL function json_build_array(variadic "any")
+ * SQL function json_build_object_ext(absent_on_null bool, unique bool, variadic "any")
  */
 Datum
-json_build_array(PG_FUNCTION_ARGS)
+json_build_object_ext(PG_FUNCTION_ARGS)
+{
+	return json_build_object_worker(fcinfo, 2,
+									PG_GETARG_BOOL(0), PG_GETARG_BOOL(1));
+}
+
+/*
+ * degenerate case of json_build_object where it gets 0 arguments.
+ */
+Datum
+json_build_object_noargs(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TEXT_P(cstring_to_text_with_len("{}", 2));
+}
+
+static Datum
+json_build_array_worker(FunctionCallInfo fcinfo, int first_vararg,
+						bool absent_on_null)
 {
 	int			nargs;
 	int			i;
@@ -2271,7 +2534,8 @@ json_build_array(PG_FUNCTION_ARGS)
 	Oid		   *types;
 
 	/* fetch argument values to build the array */
-	nargs = extract_variadic_args(fcinfo, 0, false, &args, &types, &nulls);
+	nargs = extract_variadic_args(fcinfo, first_vararg, false,
+								  &args, &types, &nulls);
 
 	if (nargs < 0)
 		PG_RETURN_NULL();
@@ -2282,6 +2546,9 @@ json_build_array(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < nargs; i++)
 	{
+		if (absent_on_null && nulls[i])
+			continue;
+
 		appendStringInfoString(result, sep);
 		sep = ", ";
 		add_json(args[i], nulls[i], result, types[i], false);
@@ -2293,6 +2560,24 @@ json_build_array(PG_FUNCTION_ARGS)
 }
 
 /*
+ * SQL function json_build_array(variadic "any")
+ */
+Datum
+json_build_array(PG_FUNCTION_ARGS)
+{
+	return json_build_array_worker(fcinfo, 0, false);
+}
+
+/*
+ * SQL function json_build_array_ext(absent_on_null bool, variadic "any")
+ */
+Datum
+json_build_array_ext(PG_FUNCTION_ARGS)
+{
+	return json_build_array_worker(fcinfo, 1, PG_GETARG_BOOL(0));
+}
+
+/*
  * degenerate case of json_build_array where it gets 0 arguments.
  */
 Datum
@@ -2523,6 +2808,178 @@ escape_json(StringInfo buf, const char *str)
 	appendStringInfoCharMacro(buf, '"');
 }
 
+/* Functions implementing hash table for key uniqueness check */
+static int
+json_unique_hash_match(const void *key1, const void *key2, Size keysize)
+{
+	return strcmp(*(const char **) key1, *(const char **) key2);
+}
+
+static void *
+json_unique_hash_keycopy(void *dest, const void *src, Size keysize)
+{
+	*(const char **) dest = pstrdup(*(const char **) src);
+
+	return dest;
+}
+
+static uint32
+json_unique_hash(const void *key, Size keysize)
+{
+	const char *s = *(const char **) key;
+
+	return DatumGetUInt32(hash_any((const unsigned char *) s, (int) strlen(s)));
+}
+
+/* Semantic actions for key uniqueness check */
+static void
+json_unique_object_start(void *_state)
+{
+	JsonUniqueState *state = _state;
+	JsonObjectFields *obj = palloc(sizeof(*obj));
+	HASHCTL		ctl;
+
+	memset(&ctl, 0, sizeof(ctl));
+	ctl.keysize = sizeof(char *);
+	ctl.entrysize = sizeof(char *);
+	ctl.hcxt = CurrentMemoryContext;
+	ctl.hash = json_unique_hash;
+	ctl.keycopy = json_unique_hash_keycopy;
+	ctl.match = json_unique_hash_match;
+	obj->fields = hash_create("json object hashtable",
+							  32,
+							  &ctl,
+							  HASH_ELEM | HASH_CONTEXT |
+							  HASH_FUNCTION | HASH_COMPARE | HASH_KEYCOPY);
+	obj->parent = state->stack;		/* push object to stack */
+
+	state->stack = obj;
+}
+
+static void
+json_unique_object_end(void *_state)
+{
+	JsonUniqueState *state = _state;
+
+	hash_destroy(state->stack->fields);
+
+	state->stack = state->stack->parent;	/* pop object from stack */
+}
+
+static void
+json_unique_object_field_start(void *_state, char *field, bool isnull)
+{
+	JsonUniqueState *state = _state;
+	bool		found;
+
+	/* find key collision in the current object */
+	(void) hash_search(state->stack->fields, &field, HASH_ENTER, &found);
+
+	if (found)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("duplicate JSON key \"%s\"", field),
+				 report_json_context(state->lex)));
+}
+
+/*
+ * json_is_valid -- check json text validity, its value type and key uniqueness
+ */
+Datum
+json_is_valid(PG_FUNCTION_ARGS)
+{
+	text	   *json = PG_GETARG_TEXT_P(0);
+	text	   *type = PG_GETARG_TEXT_P(1);
+	bool		unique = PG_GETARG_BOOL(2);
+	MemoryContext mcxt = CurrentMemoryContext;
+
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+
+	if (!PG_ARGISNULL(1) &&
+		strncmp("any", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+	{
+		JsonLexContext *lex;
+		JsonTokenType tok;
+
+		lex = makeJsonLexContext(json, false);
+
+		/* Lex exactly one token from the input and check its type. */
+		PG_TRY();
+		{
+			json_lex(lex);
+		}
+		PG_CATCH();
+		{
+			if (ERRCODE_TO_CATEGORY(geterrcode()) == ERRCODE_DATA_EXCEPTION)
+			{
+				FlushErrorState();
+				MemoryContextSwitchTo(mcxt);
+				PG_RETURN_BOOL(false);	/* invalid json */
+			}
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+
+		tok = lex_peek(lex);
+
+		if (!strncmp("object", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+		{
+			if (tok != JSON_TOKEN_OBJECT_START)
+				PG_RETURN_BOOL(false);	/* json is not a object */
+		}
+		else if (!strncmp("array", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+		{
+			if (tok != JSON_TOKEN_ARRAY_START)
+				PG_RETURN_BOOL(false);	/* json is not an array */
+		}
+		else
+		{
+			if (tok == JSON_TOKEN_OBJECT_START ||
+				tok == JSON_TOKEN_ARRAY_START)
+				PG_RETURN_BOOL(false);	/* json is not a scalar */
+		}
+	}
+
+	/* do full parsing pass only for uniqueness check or JSON text validation */
+	if (unique ||
+		get_fn_expr_argtype(fcinfo->flinfo, 0) != JSONOID)
+	{
+		JsonLexContext *lex = makeJsonLexContext(json, unique);
+		JsonSemAction uniqueSemAction = {0};
+		JsonUniqueState state;
+
+		if (unique)
+		{
+			state.lex = lex;
+			state.stack = NULL;
+
+			uniqueSemAction.semstate = &state;
+			uniqueSemAction.object_start = json_unique_object_start;
+			uniqueSemAction.object_field_start = json_unique_object_field_start;
+			uniqueSemAction.object_end = json_unique_object_end;
+		}
+
+		PG_TRY();
+		{
+			pg_parse_json(lex, unique ? &uniqueSemAction : &nullSemAction);
+		}
+		PG_CATCH();
+		{
+			if (ERRCODE_TO_CATEGORY(geterrcode()) == ERRCODE_DATA_EXCEPTION)
+			{
+				FlushErrorState();
+				MemoryContextSwitchTo(mcxt);
+				PG_RETURN_BOOL(false);	/* invalid json or key collision found */
+			}
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+	}
+
+	PG_RETURN_BOOL(true);	/* ok */
+}
+
 /*
  * SQL function json_typeof(json) -> text
  *
diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 0f20162..f3b6b45 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -52,6 +52,16 @@ typedef enum					/* type categories for datum_to_jsonb */
 	JSONBTYPE_OTHER				/* all else */
 } JsonbTypeCategory;
 
+/* Context for key uniqueness check */
+typedef struct JsonbUniqueCheckContext
+{
+	JsonbValue *obj;				/* object containing skipped keys also */
+	int		   *skipped_keys;		/* array of skipped key-value pair indices */
+	int			skipped_keys_allocated;
+	int			skipped_keys_count;
+	MemoryContext mcxt;				/* context for saving skipped keys */
+} JsonbUniqueCheckContext;
+
 typedef struct JsonbAggState
 {
 	JsonbInState *res;
@@ -59,6 +69,7 @@ typedef struct JsonbAggState
 	Oid			key_output_func;
 	JsonbTypeCategory val_category;
 	Oid			val_output_func;
+	JsonbUniqueCheckContext unique_check;
 } JsonbAggState;
 
 static inline Datum jsonb_from_cstring(char *json, int len);
@@ -1114,11 +1125,121 @@ to_jsonb(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
 }
 
+static inline void
+jsonb_unique_check_init(JsonbUniqueCheckContext *cxt, JsonbValue *obj,
+						MemoryContext mcxt)
+{
+	cxt->mcxt = mcxt;
+	cxt->obj = obj;
+	cxt->skipped_keys = NULL;
+	cxt->skipped_keys_count = 0;
+	cxt->skipped_keys_allocated = 0;
+}
+
 /*
- * SQL function jsonb_build_object(variadic "any")
+ * Save the index of the skipped key-value pair that has just been appended
+ * to the object.
  */
-Datum
-jsonb_build_object(PG_FUNCTION_ARGS)
+static inline void
+jsonb_unique_check_add_skipped(JsonbUniqueCheckContext *cxt)
+{
+	/*
+	 * Make a room for the skipped index plus one additional index
+	 * (see jsonb_unique_check_remove_skipped_keys()).
+	 */
+	if (cxt->skipped_keys_count + 1 >= cxt->skipped_keys_allocated)
+	{
+		if (cxt->skipped_keys_allocated)
+		{
+			cxt->skipped_keys_allocated *= 2;
+			cxt->skipped_keys = repalloc(cxt->skipped_keys,
+										 sizeof(*cxt->skipped_keys) *
+										 cxt->skipped_keys_allocated);
+		}
+		else
+		{
+			cxt->skipped_keys_allocated = 16;
+			cxt->skipped_keys = MemoryContextAlloc(cxt->mcxt,
+												   sizeof(*cxt->skipped_keys) *
+												   cxt->skipped_keys_allocated);
+		}
+	}
+
+	cxt->skipped_keys[cxt->skipped_keys_count++] = cxt->obj->val.object.nPairs;
+}
+
+/*
+ * Check uniqueness of the key that has just been appended to the object.
+ */
+static inline void
+jsonb_unique_check_key(JsonbUniqueCheckContext *cxt, bool skip)
+{
+	JsonbPair *pair = cxt->obj->val.object.pairs;
+	/* nPairs is incremented only after the value is appended */
+	JsonbPair *last = &pair[cxt->obj->val.object.nPairs];
+
+	for (; pair < last; pair++)
+		if (pair->key.val.string.len ==
+			last->key.val.string.len &&
+			!memcmp(pair->key.val.string.val,
+					last->key.val.string.val,
+					last->key.val.string.len))
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_JSON_OBJECT_KEY_VALUE),
+					 errmsg("duplicate JSON key \"%*s\"",
+							last->key.val.string.len,
+							last->key.val.string.val)));
+
+	if (skip)
+	{
+		/* save skipped key index */
+		jsonb_unique_check_add_skipped(cxt);
+
+		/* add dummy null value for the skipped key */
+		last->value.type = jbvNull;
+		cxt->obj->val.object.nPairs++;
+	}
+}
+
+/*
+ * Remove skipped key-value pairs from the resulting object.
+ */
+static void
+jsonb_unique_check_remove_skipped_keys(JsonbUniqueCheckContext *cxt)
+{
+	int		   *skipped_keys = cxt->skipped_keys;
+	int			skipped_keys_count = cxt->skipped_keys_count;
+
+	if (!skipped_keys_count)
+		return;
+
+	if (cxt->obj->val.object.nPairs > skipped_keys_count)
+	{
+		/* remove skipped key-value pairs */
+		JsonbPair  *pairs = cxt->obj->val.object.pairs;
+		int			i;
+
+		/* save total pair count into the last element of skipped_keys */
+		Assert(cxt->skipped_keys_count < cxt->skipped_keys_allocated);
+		cxt->skipped_keys[cxt->skipped_keys_count] = cxt->obj->val.object.nPairs;
+
+		for (i = 0; i < skipped_keys_count; i++)
+		{
+			int			skipped_key = skipped_keys[i];
+			int			nkeys = skipped_keys[i + 1] - skipped_key - 1;
+
+			memmove(&pairs[skipped_key - i],
+					&pairs[skipped_key + 1],
+					sizeof(JsonbPair) * nkeys);
+		}
+	}
+
+	cxt->obj->val.object.nPairs -= skipped_keys_count;
+}
+
+static Datum
+jsonb_build_object_worker(FunctionCallInfo fcinfo, int first_vararg,
+						  bool absent_on_null, bool unique_keys)
 {
 	int			nargs;
 	int			i;
@@ -1126,9 +1247,11 @@ jsonb_build_object(PG_FUNCTION_ARGS)
 	Datum	   *args;
 	bool	   *nulls;
 	Oid		   *types;
+	JsonbUniqueCheckContext unique_check;
 
 	/* build argument values to build the object */
-	nargs = extract_variadic_args(fcinfo, 0, true, &args, &types, &nulls);
+	nargs = extract_variadic_args(fcinfo, first_vararg, true,
+								  &args, &types, &nulls);
 
 	if (nargs < 0)
 		PG_RETURN_NULL();
@@ -1143,26 +1266,69 @@ jsonb_build_object(PG_FUNCTION_ARGS)
 
 	result.res = pushJsonbValue(&result.parseState, WJB_BEGIN_OBJECT, NULL);
 
+	/* if (unique_keys) */
+	jsonb_unique_check_init(&unique_check, result.res, CurrentMemoryContext);
+
 	for (i = 0; i < nargs; i += 2)
 	{
 		/* process key */
+		bool		skip;
+
 		if (nulls[i])
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("argument %d: key must not be null", i + 1)));
+					 errmsg("argument %d: key must not be null",
+							first_vararg + i + 1)));
+
+		/* skip null values if absent_on_null */
+		skip = absent_on_null && nulls[i + 1];
+
+		/* we need to save skipped keys for the key uniqueness check */
+		if (skip && !unique_keys)
+			continue;
 
 		add_jsonb(args[i], false, &result, types[i], true);
 
+		if (unique_keys)
+		{
+			jsonb_unique_check_key(&unique_check, skip);
+
+			if (skip)
+				continue;	/* do not process the value if the key is skipped */
+		}
+
 		/* process value */
 		add_jsonb(args[i + 1], nulls[i + 1], &result, types[i + 1], false);
 	}
 
+	if (unique_keys && absent_on_null)
+		jsonb_unique_check_remove_skipped_keys(&unique_check);
+
 	result.res = pushJsonbValue(&result.parseState, WJB_END_OBJECT, NULL);
 
 	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
 }
 
 /*
+ * SQL function jsonb_build_object(variadic "any")
+ */
+Datum
+jsonb_build_object(PG_FUNCTION_ARGS)
+{
+	return jsonb_build_object_worker(fcinfo, 0, false, false);
+}
+
+/*
+ * SQL function jsonb_build_object_ext(absent_on_null bool, unique bool, variadic "any")
+ */
+Datum
+jsonb_build_object_ext(PG_FUNCTION_ARGS)
+{
+	return jsonb_build_object_worker(fcinfo, 2,
+									 PG_GETARG_BOOL(0), PG_GETARG_BOOL(1));
+}
+
+/*
  * degenerate case of jsonb_build_object where it gets 0 arguments.
  */
 Datum
@@ -1178,11 +1344,9 @@ jsonb_build_object_noargs(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
 }
 
-/*
- * SQL function jsonb_build_array(variadic "any")
- */
-Datum
-jsonb_build_array(PG_FUNCTION_ARGS)
+static Datum
+jsonb_build_array_worker(FunctionCallInfo fcinfo, int first_vararg,
+						 bool absent_on_null)
 {
 	int			nargs;
 	int			i;
@@ -1192,7 +1356,8 @@ jsonb_build_array(PG_FUNCTION_ARGS)
 	Oid		   *types;
 
 	/* build argument values to build the array */
-	nargs = extract_variadic_args(fcinfo, 0, true, &args, &types, &nulls);
+	nargs = extract_variadic_args(fcinfo, first_vararg, true,
+								  &args, &types, &nulls);
 
 	if (nargs < 0)
 		PG_RETURN_NULL();
@@ -1202,7 +1367,12 @@ jsonb_build_array(PG_FUNCTION_ARGS)
 	result.res = pushJsonbValue(&result.parseState, WJB_BEGIN_ARRAY, NULL);
 
 	for (i = 0; i < nargs; i++)
+	{
+		if (absent_on_null && nulls[i])
+			continue;
+
 		add_jsonb(args[i], nulls[i], &result, types[i], false);
+	}
 
 	result.res = pushJsonbValue(&result.parseState, WJB_END_ARRAY, NULL);
 
@@ -1210,6 +1380,24 @@ jsonb_build_array(PG_FUNCTION_ARGS)
 }
 
 /*
+ * SQL function jsonb_build_array(variadic "any")
+ */
+Datum
+jsonb_build_array(PG_FUNCTION_ARGS)
+{
+	return jsonb_build_array_worker(fcinfo, 0, false);
+}
+
+/*
+ * SQL function jsonb_build_array_ext(absent_on_null bool, variadic "any")
+ */
+Datum
+jsonb_build_array_ext(PG_FUNCTION_ARGS)
+{
+	return jsonb_build_array_worker(fcinfo, 1, PG_GETARG_BOOL(0));
+}
+
+/*
  * degenerate case of jsonb_build_array where it gets 0 arguments.
  */
 Datum
@@ -1460,12 +1648,8 @@ clone_parse_state(JsonbParseState *state)
 	return result;
 }
 
-
-/*
- * jsonb_agg aggregate function
- */
-Datum
-jsonb_agg_transfn(PG_FUNCTION_ARGS)
+static Datum
+jsonb_agg_transfn_worker(FunctionCallInfo fcinfo, bool absent_on_null)
 {
 	MemoryContext oldcontext,
 				aggcontext;
@@ -1513,6 +1697,9 @@ jsonb_agg_transfn(PG_FUNCTION_ARGS)
 		result = state->res;
 	}
 
+	if (absent_on_null && PG_ARGISNULL(1))
+		PG_RETURN_POINTER(state);
+
 	/* turn the argument into jsonb in the normal function context */
 
 	val = PG_ARGISNULL(1) ? (Datum) 0 : PG_GETARG_DATUM(1);
@@ -1582,6 +1769,24 @@ jsonb_agg_transfn(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state);
 }
 
+/*
+ * jsonb_agg aggregate function
+ */
+Datum
+jsonb_agg_transfn(PG_FUNCTION_ARGS)
+{
+	return jsonb_agg_transfn_worker(fcinfo, false);
+}
+
+/*
+ * jsonb_agg_strict aggregate function
+ */
+Datum
+jsonb_agg_strict_transfn(PG_FUNCTION_ARGS)
+{
+	return jsonb_agg_transfn_worker(fcinfo, true);
+}
+
 Datum
 jsonb_agg_finalfn(PG_FUNCTION_ARGS)
 {
@@ -1614,11 +1819,9 @@ jsonb_agg_finalfn(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(out);
 }
 
-/*
- * jsonb_object_agg aggregate function
- */
-Datum
-jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
+static Datum
+jsonb_object_agg_transfn_worker(FunctionCallInfo fcinfo,
+								bool absent_on_null, bool unique_keys)
 {
 	MemoryContext oldcontext,
 				aggcontext;
@@ -1632,6 +1835,7 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
 			   *jbval;
 	JsonbValue	v;
 	JsonbIteratorToken type;
+	bool		skip;
 
 	if (!AggCheckCallContext(fcinfo, &aggcontext))
 	{
@@ -1651,6 +1855,11 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
 		state->res = result;
 		result->res = pushJsonbValue(&result->parseState,
 									 WJB_BEGIN_OBJECT, NULL);
+		if (unique_keys)
+			jsonb_unique_check_init(&state->unique_check, result->res,
+									aggcontext);
+		else
+			memset(&state->unique_check, 0, sizeof(state->unique_check));
 		MemoryContextSwitchTo(oldcontext);
 
 		arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
@@ -1686,6 +1895,15 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("field name must not be null")));
 
+	/*
+	 * Skip null values if absent_on_null unless key uniqueness check is
+	 * needed (because we must save keys in this case).
+	 */
+	skip = absent_on_null && PG_ARGISNULL(2);
+
+	if (skip && !unique_keys)
+		PG_RETURN_POINTER(state);
+
 	val = PG_GETARG_DATUM(1);
 
 	memset(&elem, 0, sizeof(JsonbInState));
@@ -1741,6 +1959,18 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
 				}
 				result->res = pushJsonbValue(&result->parseState,
 											 WJB_KEY, &v);
+
+				if (unique_keys)
+				{
+					jsonb_unique_check_key(&state->unique_check, skip);
+
+					if (skip)
+					{
+						MemoryContextSwitchTo(oldcontext);
+						PG_RETURN_POINTER(state);
+					}
+				}
+
 				break;
 			case WJB_END_ARRAY:
 				break;
@@ -1813,6 +2043,26 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state);
 }
 
+/*
+ * jsonb_object_agg aggregate function
+ */
+Datum
+jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
+{
+	return jsonb_object_agg_transfn_worker(fcinfo, false, false);
+}
+
+/*
+ * jsonb_objectagg aggregate function
+ */
+Datum
+jsonb_objectagg_transfn(PG_FUNCTION_ARGS)
+{
+	return jsonb_object_agg_transfn_worker(fcinfo,
+										   PG_GETARG_BOOL(3),
+										   PG_GETARG_BOOL(4));
+}
+
 Datum
 jsonb_object_agg_finalfn(PG_FUNCTION_ARGS)
 {
@@ -1847,6 +2097,41 @@ jsonb_object_agg_finalfn(PG_FUNCTION_ARGS)
 }
 
 /*
+ * jsonb_is_valid -- check jsonb value type
+ */
+Datum
+jsonb_is_valid(PG_FUNCTION_ARGS)
+{
+	Jsonb	   *jb = PG_GETARG_JSONB_P(0);
+	text	   *type = PG_GETARG_TEXT_P(1);
+
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+
+	if (!PG_ARGISNULL(1) &&
+		strncmp("any", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+	{
+		if (!strncmp("object", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+		{
+			if (!JB_ROOT_IS_OBJECT(jb))
+				PG_RETURN_BOOL(false);
+		}
+		else if (!strncmp("array", VARDATA(type), VARSIZE_ANY_EXHDR(type)))
+		{
+			if (!JB_ROOT_IS_ARRAY(jb) || JB_ROOT_IS_SCALAR(jb))
+				PG_RETURN_BOOL(false);
+		}
+		else
+		{
+			if (!JB_ROOT_IS_ARRAY(jb) || !JB_ROOT_IS_SCALAR(jb))
+				PG_RETURN_BOOL(false);
+		}
+	}
+
+	PG_RETURN_BOOL(true);
+}
+
+/*
  * Extract scalar value from raw-scalar pseudo-array jsonb.
  */
 JsonbValue *
@@ -1869,3 +2154,65 @@ JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res)
 
 	return res;
 }
+
+/*
+ * Construct an empty array jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyArray(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvArray;
+	jbv.val.array.elems = NULL;
+	jbv.val.array.nElems = 0;
+	jbv.val.array.rawScalar = false;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Construct an empty object jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyObject(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvObject;
+	jbv.val.object.pairs = NULL;
+	jbv.val.object.nPairs = 0;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Convert jsonb to a C-string stripping quotes from scalar strings.
+ */
+char *
+JsonbUnquote(Jsonb *jb)
+{
+	if (JB_ROOT_IS_SCALAR(jb))
+	{
+		JsonbValue	v;
+
+		JsonbExtractScalar(&jb->root, &v);
+
+		if (v.type == jbvString)
+			return pnstrdup(v.val.string.val, v.val.string.len);
+		else if (v.type == jbvBool)
+			return pstrdup(v.val.boolean ? "true" : "false");
+		else if (v.type == jbvNumeric)
+			return DatumGetCString(DirectFunctionCall1(numeric_out,
+									   PointerGetDatum(v.val.numeric)));
+		else if (v.type == jbvNull)
+			return pstrdup("null");
+		else
+		{
+			elog(ERROR, "unrecognized jsonb value type %d", v.type);
+			return NULL;
+		}
+	}
+	else
+		return JsonbToCString(NULL, &jb->root, VARSIZE(jb));
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index fa78451..2fe2f01 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -3047,6 +3047,50 @@ populate_record_field(ColumnIOData *col,
 	}
 }
 
+/* recursively populate specified type from a json/jsonb value */
+Datum
+json_populate_type(Datum json_val, Oid json_type, Oid typid, int32 typmod,
+				   void **cache, MemoryContext mcxt, bool *isnull)
+{
+	JsValue		jsv = { 0 };
+	JsonbValue	jbv;
+
+	jsv.is_json = json_type == JSONOID;
+
+	if (*isnull)
+	{
+		if (jsv.is_json)
+			jsv.val.json.str = NULL;
+		else
+			jsv.val.jsonb = NULL;
+	}
+	else if (jsv.is_json)
+	{
+		text	   *json = DatumGetTextPP(json_val);
+
+		jsv.val.json.str = VARDATA_ANY(json);
+		jsv.val.json.len = VARSIZE_ANY_EXHDR(json);
+		jsv.val.json.type = JSON_TOKEN_INVALID; /* not used in populate_composite() */
+	}
+	else
+	{
+		Jsonb	   *jsonb = DatumGetJsonbP(json_val);
+
+		jsv.val.jsonb = &jbv;
+
+		/* fill binary jsonb value pointing to jb */
+		jbv.type = jbvBinary;
+		jbv.val.binary.data = &jsonb->root;
+		jbv.val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+	}
+
+	if (!*cache)
+		*cache = MemoryContextAllocZero(mcxt, sizeof(ColumnIOData));
+
+	return populate_record_field(*cache , typid, typmod, NULL, mcxt,
+								 PointerGetDatum(NULL), &jsv, isnull);
+}
+
 static RecordIOData *
 allocate_record_info(MemoryContext mcxt, int ncolumns)
 {
diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index ee5fcf2..dd36829 100644
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -2699,3 +2699,104 @@ wrapItemsInArray(const JsonValueList *items)
 
 	return pushJsonbValue(&ps, WJB_END_ARRAY, NULL);
 }
+
+/********************Interface to pgsql's executor***************************/
+bool
+JsonbPathExists(Datum jb, JsonPath *jp, List *vars)
+{
+	JsonPathExecResult res = executeJsonPath(jp, vars, DatumGetJsonbP(jb),
+											 NULL);
+
+	throwJsonPathError(res);
+
+	return res == jperOk;
+}
+
+Datum
+JsonbPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper,
+			   bool *empty, List *vars)
+{
+	JsonbValue *first;
+	bool		wrap;
+	JsonValueList found = { 0 };
+	JsonPathExecResult jper = executeJsonPath(jp, vars, DatumGetJsonbP(jb),
+											  &found);
+	int			count;
+
+	throwJsonPathError(jper);
+
+	count = JsonValueListLength(&found);
+
+	first = count ? JsonValueListHead(&found) : NULL;
+
+	if (!first)
+		wrap = false;
+	else if (wrapper == JSW_NONE)
+		wrap = false;
+	else if (wrapper == JSW_UNCONDITIONAL)
+		wrap = true;
+	else if (wrapper == JSW_CONDITIONAL)
+		wrap = count > 1 ||
+			IsAJsonbScalar(first) ||
+			(first->type == jbvBinary &&
+			 JsonContainerIsScalar(first->val.binary.data));
+	else
+	{
+		elog(ERROR, "unrecognized json wrapper %d", wrapper);
+		wrap = false;
+	}
+
+	if (wrap)
+		return JsonbPGetDatum(JsonbValueToJsonb(wrapItemsInArray(&found)));
+
+	if (count > 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_MORE_THAN_ONE_JSON_ITEM),
+				 errmsg("more than one SQL/JSON item")));
+
+	if (first)
+		return JsonbPGetDatum(JsonbValueToJsonb(first));
+
+	*empty = true;
+	return PointerGetDatum(NULL);
+}
+
+JsonbValue *
+JsonbPathValue(Datum jb, JsonPath *jp, bool *empty, List *vars)
+{
+	JsonbValue *res;
+	JsonValueList found = { 0 };
+	JsonPathExecResult jper = executeJsonPath(jp, vars, DatumGetJsonbP(jb),
+											  &found);
+	int			count;
+
+	throwJsonPathError(jper);
+
+	count = JsonValueListLength(&found);
+
+	*empty = !count;
+
+	if (*empty)
+		return NULL;
+
+	if (count > 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_MORE_THAN_ONE_JSON_ITEM),
+				 errmsg("more than one SQL/JSON item")));
+
+	res = JsonValueListHead(&found);
+
+	if (res->type == jbvBinary &&
+		JsonContainerIsScalar(res->val.binary.data))
+		JsonbExtractScalar(res->val.binary.data, res);
+
+	if (!IsAJsonbScalar(res))
+		ereport(ERROR,
+				(errcode(ERRCODE_JSON_SCALAR_REQUIRED),
+				 errmsg("SQL/JSON scalar required")));
+
+	if (res->type == jbvNull)
+		return NULL;
+
+	return res;
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index be46c00..a167232 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -465,6 +465,8 @@ static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
 static char *generate_qualified_type_name(Oid typid);
 static text *string_to_text(char *str);
 static char *flatten_reloptions(Oid relid);
+static void get_json_path_spec(Node *path_spec, deparse_context *context,
+				   bool showimplicit);
 
 #define only_marker(rte)  ((rte)->inh ? "" : "ONLY ")
 
@@ -7358,6 +7360,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 		case T_Aggref:
 		case T_WindowFunc:
 		case T_FuncExpr:
+		case T_JsonExpr:
 			/* function-like: name(..) or name[..] */
 			return true;
 
@@ -7476,6 +7479,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 				case T_Aggref:	/* own parentheses */
 				case T_WindowFunc:	/* own parentheses */
 				case T_CaseExpr:	/* other separators */
+				case T_JsonExpr: /* own parentheses */
 					return true;
 				default:
 					return false;
@@ -7639,6 +7643,61 @@ get_rule_expr_paren(Node *node, deparse_context *context,
 
 
 /*
+ * get_json_path_spec		- Parse back a JSON path specification
+ */
+static void
+get_json_path_spec(Node *path_spec, deparse_context *context, bool showimplicit)
+{
+	if (IsA(path_spec, Const))
+		get_const_expr((Const *) path_spec, context, -1);
+	else
+		get_rule_expr(path_spec, context, showimplicit);
+}
+
+/*
+ * get_json_format			- Parse back a JsonFormat structure
+ */
+static void
+get_json_format(JsonFormat *format, deparse_context *context)
+{
+	if (format->type == JS_FORMAT_DEFAULT)
+		return;
+
+	appendStringInfoString(context->buf,
+						   format->type == JS_FORMAT_JSONB ?
+						   " FORMAT JSONB" : " FORMAT JSON");
+
+	if (format->encoding != JS_ENC_DEFAULT)
+	{
+		const char *encoding =
+			format->encoding == JS_ENC_UTF16 ? "UTF16" :
+			format->encoding == JS_ENC_UTF32 ? "UTF32" : "UTF8";
+
+		appendStringInfo(context->buf, " ENCODING %s", encoding);
+	}
+}
+
+/*
+ * get_json_returning		- Parse back a JsonReturning structure
+ */
+static void
+get_json_returning(JsonReturning *returning, deparse_context *context,
+				   bool json_format_by_default)
+{
+	if (!OidIsValid(returning->typid))
+		return;
+
+	appendStringInfo(context->buf, " RETURNING %s",
+					 format_type_with_typemod(returning->typid,
+											  returning->typmod));
+
+	if (!json_format_by_default ||
+		returning->format.type !=
+			(returning->typid == JSONBOID ? JS_FORMAT_JSONB : JS_FORMAT_JSON))
+		get_json_format(&returning->format, context);
+}
+
+/*
  * get_coercion				- Parse back a coercion
  */
 static void
@@ -7657,6 +7716,54 @@ get_coercion(Expr *arg, deparse_context *context, bool showimplicit,
 	}
 }
 
+static void
+get_json_behavior(JsonBehavior *behavior, deparse_context *context,
+				  const char *on)
+{
+	switch (behavior->btype)
+	{
+		case JSON_BEHAVIOR_DEFAULT:
+			appendStringInfoString(context->buf, " DEFAULT ");
+			get_rule_expr(behavior->default_expr, context, false);
+			break;
+
+		case JSON_BEHAVIOR_EMPTY:
+			appendStringInfoString(context->buf, " EMPTY");
+			break;
+
+		case JSON_BEHAVIOR_EMPTY_ARRAY:
+			appendStringInfoString(context->buf, " EMPTY ARRAY");
+			break;
+
+		case JSON_BEHAVIOR_EMPTY_OBJECT:
+			appendStringInfoString(context->buf, " EMPTY OBJECT");
+			break;
+
+		case JSON_BEHAVIOR_ERROR:
+			appendStringInfoString(context->buf, " ERROR");
+			break;
+
+		case JSON_BEHAVIOR_FALSE:
+			appendStringInfoString(context->buf, " FALSE");
+			break;
+
+		case JSON_BEHAVIOR_NULL:
+			appendStringInfoString(context->buf, " NULL");
+			break;
+
+		case JSON_BEHAVIOR_TRUE:
+			appendStringInfoString(context->buf, " TRUE");
+			break;
+
+		case JSON_BEHAVIOR_UNKNOWN:
+			appendStringInfoString(context->buf, " UNKNOWN");
+			break;
+	}
+
+	appendStringInfo(context->buf, " ON %s", on);
+}
+
+
 /* ----------
  * get_rule_expr			- Parse back an expression
  *
@@ -8771,6 +8878,83 @@ get_rule_expr(Node *node, deparse_context *context,
 			}
 			break;
 
+
+		case T_JsonValueExpr:
+			{
+				JsonValueExpr *jve = (JsonValueExpr *) node;
+
+				get_rule_expr((Node *) jve->expr, context, false);
+				get_json_format(&jve->format, context);
+			}
+			break;
+
+		case T_JsonExpr:
+			{
+				JsonExpr   *jexpr = (JsonExpr *) node;
+
+				switch (jexpr->op)
+				{
+					case IS_JSON_QUERY:
+						appendStringInfoString(buf, "JSON_QUERY(");
+						break;
+					case IS_JSON_VALUE:
+						appendStringInfoString(buf, "JSON_VALUE(");
+						break;
+					case IS_JSON_EXISTS:
+						appendStringInfoString(buf, "JSON_EXISTS(");
+						break;
+				}
+
+				get_rule_expr(jexpr->raw_expr, context, showimplicit);
+
+				get_json_format(&jexpr->format, context);
+
+				appendStringInfoString(buf, ", ");
+
+				get_json_path_spec(jexpr->path_spec, context, showimplicit);
+
+				if (jexpr->passing.values)
+				{
+					ListCell   *lc1, *lc2;
+					bool		needcomma = false;
+
+					appendStringInfoString(buf, " PASSING ");
+
+					forboth(lc1, jexpr->passing.names,
+							lc2, jexpr->passing.values)
+					{
+						if (needcomma)
+							appendStringInfoString(buf, ", ");
+						needcomma = true;
+
+						get_rule_expr((Node *) lfirst(lc2), context, showimplicit);
+						appendStringInfo(buf, " AS %s",
+										 ((Value *) lfirst(lc1))->val.str);
+					}
+				}
+
+				if (jexpr->op != IS_JSON_EXISTS)
+					get_json_returning(&jexpr->returning, context,
+									   jexpr->op != IS_JSON_VALUE);
+
+				if (jexpr->wrapper == JSW_CONDITIONAL)
+					appendStringInfo(buf, " WITH CONDITIONAL WRAPPER");
+
+				if (jexpr->wrapper == JSW_UNCONDITIONAL)
+					appendStringInfo(buf, " WITH UNCONDITIONAL WRAPPER");
+
+				if (jexpr->omit_quotes)
+					appendStringInfo(buf, " OMIT QUOTES");
+
+				if (jexpr->op != IS_JSON_EXISTS)
+					get_json_behavior(&jexpr->on_empty, context, "EMPTY");
+
+				get_json_behavior(&jexpr->on_error, context, "ERROR");
+
+				appendStringInfoString(buf, ")");
+			}
+			break;
+
 		case T_List:
 			{
 				char	   *sep;
@@ -8867,6 +9051,7 @@ looks_like_function(Node *node)
 		case T_MinMaxExpr:
 		case T_SQLValueFunction:
 		case T_XmlExpr:
+		case T_JsonExpr:
 			/* these are all accepted by func_expr_common_subexpr */
 			return true;
 		default:
@@ -8942,6 +9127,66 @@ get_func_opts(FuncFormat aggformat, Node *aggformatopts, deparse_context *contex
 {
 	switch (aggformat)
 	{
+		case FUNCFMT_JSON_OBJECT:
+		case FUNCFMT_JSON_OBJECTAGG:
+		case FUNCFMT_JSON_ARRAY:
+		case FUNCFMT_JSON_ARRAYAGG:
+			{
+				JsonCtorOpts *opts = castNode(JsonCtorOpts, aggformatopts);
+
+				if (!opts)
+					break;
+
+				if (opts->absent_on_null)
+				{
+					if (aggformat == FUNCFMT_JSON_OBJECT ||
+						aggformat == FUNCFMT_JSON_OBJECTAGG)
+						appendStringInfoString(context->buf, " ABSENT ON NULL");
+				}
+				else
+				{
+					if (aggformat == FUNCFMT_JSON_ARRAY ||
+						aggformat == FUNCFMT_JSON_ARRAYAGG)
+						appendStringInfoString(context->buf, " NULL ON NULL");
+				}
+
+				if (opts->unique)
+					appendStringInfoString(context->buf, " WITH UNIQUE KEYS");
+
+				get_json_returning(&opts->returning, context, true);
+			}
+			break;
+
+		case FUNCFMT_IS_JSON:
+			{
+				JsonIsPredicateOpts *opts =
+					castNode(JsonIsPredicateOpts, aggformatopts);
+
+				appendStringInfoString(context->buf, " IS JSON");
+
+				if (!opts)
+					break;
+
+				switch (opts->value_type)
+				{
+					case JS_TYPE_SCALAR:
+						appendStringInfoString(context->buf, " SCALAR");
+						break;
+					case JS_TYPE_ARRAY:
+						appendStringInfoString(context->buf, " ARRAY");
+						break;
+					case JS_TYPE_OBJECT:
+						appendStringInfoString(context->buf, " OBJECT");
+						break;
+					default:
+						break;
+				}
+
+				if (opts->unique_keys)
+					appendStringInfoString(context->buf, " WITH UNIQUE KEYS");
+			}
+			break;
+
 		default:
 			break;
 	}
@@ -8958,6 +9203,8 @@ get_func_expr(FuncExpr *expr, deparse_context *context,
 	Oid			funcoid = expr->funcid;
 	Oid			argtypes[FUNC_MAX_ARGS];
 	int			nargs;
+	int			firstarg;
+	int			lastarg = list_length(expr->args);
 	List	   *argnames;
 	bool		use_variadic;
 	ListCell   *l;
@@ -9018,22 +9265,57 @@ get_func_expr(FuncExpr *expr, deparse_context *context,
 
 	switch (expr->funcformat2)
 	{
+		case FUNCFMT_JSON_OBJECT:
+			funcname = "JSON_OBJECT";
+			firstarg = 2;
+			use_variadic = false;
+			break;
+
+		case FUNCFMT_JSON_ARRAY:
+			funcname = "JSON_ARRAY";
+			firstarg = 1;
+			use_variadic = false;
+			break;
+
+		case FUNCFMT_IS_JSON:
+			funcname = NULL;
+			firstarg = 0;
+			lastarg = 0;
+			use_variadic = false;
+			break;
+
 		default:
 			funcname = generate_function_name(funcoid, nargs,
 											  argnames, argtypes,
 											  expr->funcvariadic,
 											  &use_variadic,
 											  context->special_exprkind);
+			firstarg = 0;
 			break;
 	}
 
-	appendStringInfo(buf, "%s(", funcname);
+	if (funcname)
+		appendStringInfo(buf, "%s(", funcname);
+	else if (!PRETTY_PAREN(context))
+		appendStringInfoChar(buf, '(');
 
 	nargs = 0;
 	foreach(l, expr->args)
 	{
-		if (nargs++ > 0)
-			appendStringInfoString(buf, ", ");
+		if (nargs > lastarg)
+			break;
+
+		if (nargs++ < firstarg)
+			continue;
+
+		if (nargs > firstarg + 1)
+		{
+			const char *sep = expr->funcformat2 == FUNCFMT_JSON_OBJECT &&
+				!((nargs - firstarg) % 2) ? " : " : ", ";
+
+			appendStringInfoString(buf, sep);
+		}
+
 		if (use_variadic && lnext(l) == NULL)
 			appendStringInfoString(buf, "VARIADIC ");
 		get_rule_expr((Node *) lfirst(l), context, true);
@@ -9041,7 +9323,8 @@ get_func_expr(FuncExpr *expr, deparse_context *context,
 
 	get_func_opts(expr->funcformat2, expr->funcformatopts, context);
 
-	appendStringInfoChar(buf, ')');
+	if (funcname || !PRETTY_PAREN(context))
+		appendStringInfoChar(buf, ')');
 }
 
 /*
@@ -9053,8 +9336,9 @@ get_agg_expr(Aggref *aggref, deparse_context *context,
 {
 	StringInfo	buf = context->buf;
 	Oid			argtypes[FUNC_MAX_ARGS];
+	const char *funcname;
 	int			nargs;
-	bool		use_variadic;
+	bool		use_variadic = false;
 
 	/*
 	 * For a combining aggregate, we look up and deparse the corresponding
@@ -9083,13 +9367,24 @@ get_agg_expr(Aggref *aggref, deparse_context *context,
 	/* Extract the argument types as seen by the parser */
 	nargs = get_aggregate_argtypes(aggref, argtypes);
 
+	switch (aggref->aggformat)
+	{
+		case FUNCFMT_JSON_OBJECTAGG:
+			funcname = "JSON_OBJECTAGG";
+			break;
+		case FUNCFMT_JSON_ARRAYAGG:
+			funcname = "JSON_ARRAYAGG";
+			break;
+		default:
+			funcname = generate_function_name(aggref->aggfnoid, nargs, NIL,
+											  argtypes, aggref->aggvariadic,
+											  &use_variadic,
+											  context->special_exprkind);
+			break;
+	}
+
 	/* Print the aggregate name, schema-qualified if needed */
-	appendStringInfo(buf, "%s(%s",
-					 generate_function_name(aggref->aggfnoid, nargs,
-											NIL, argtypes,
-											aggref->aggvariadic,
-											&use_variadic,
-											context->special_exprkind),
+	appendStringInfo(buf, "%s(%s", funcname,
 					 (aggref->aggdistinct != NIL) ? "DISTINCT " : "");
 
 	if (AGGKIND_IS_ORDERED_SET(aggref->aggkind))
@@ -9125,7 +9420,17 @@ get_agg_expr(Aggref *aggref, deparse_context *context,
 				if (tle->resjunk)
 					continue;
 				if (i++ > 0)
-					appendStringInfoString(buf, ", ");
+				{
+					if (aggref->aggformat == FUNCFMT_JSON_OBJECTAGG)
+					{
+						if (i > 2)
+							break; /* skip ABSENT ON NULL and WITH UNIQUE args */
+
+						appendStringInfoString(buf, " : ");
+					}
+					else
+						appendStringInfoString(buf, ", ");
+				}
 				if (use_variadic && i == nargs)
 					appendStringInfoString(buf, "VARIADIC ");
 				get_rule_expr(arg, context, true);
@@ -9179,6 +9484,7 @@ get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context)
 	int			nargs;
 	List	   *argnames;
 	ListCell   *l;
+	const char *funcname;
 
 	if (list_length(wfunc->args) > FUNC_MAX_ARGS)
 		ereport(ERROR,
@@ -9196,16 +9502,37 @@ get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context)
 		nargs++;
 	}
 
-	appendStringInfo(buf, "%s(",
-					 generate_function_name(wfunc->winfnoid, nargs,
-											argnames, argtypes,
-											false, NULL,
-											context->special_exprkind));
+	switch (wfunc->winformat)
+	{
+		case FUNCFMT_JSON_OBJECTAGG:
+			funcname = "JSON_OBJECTAGG";
+			break;
+		case FUNCFMT_JSON_ARRAYAGG:
+			funcname = "JSON_ARRAYAGG";
+			break;
+		default:
+			funcname = generate_function_name(wfunc->winfnoid, nargs, argnames,
+											  argtypes, false, NULL,
+											  context->special_exprkind);
+			break;
+	}
+
+	appendStringInfo(buf, "%s(", funcname);
+
 	/* winstar can be set only in zero-argument aggregates */
 	if (wfunc->winstar)
 		appendStringInfoChar(buf, '*');
 	else
-		get_rule_expr((Node *) wfunc->args, context, true);
+	{
+		if (wfunc->winformat == FUNCFMT_JSON_OBJECTAGG)
+		{
+			get_rule_expr((Node *) linitial(wfunc->args), context, false);
+			appendStringInfoString(buf, " : ");
+			get_rule_expr((Node *) lsecond(wfunc->args), context, false);
+		}
+		else
+			get_rule_expr((Node *) wfunc->args, context, true);
+	}
 
 	get_func_opts(wfunc->winformat, wfunc->winformatopts, context);
 
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 125bb5b..0d5668d 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -311,11 +311,15 @@ DATA(insert ( 3545	n 0 bytea_string_agg_transfn	bytea_string_agg_finalfn	-	-	-	-
 
 /* json */
 DATA(insert ( 3175	n 0 json_agg_transfn	json_agg_finalfn			-	-	-	-				-				-				f f r r 0	2281	0	0		0	_null_ _null_ ));
+DATA(insert ( 3450	n 0 json_agg_strict_transfn	json_agg_finalfn		-	-	-	-				-				-				f f r r 0	2281	0	0		0	_null_ _null_ ));
 DATA(insert ( 3197	n 0 json_object_agg_transfn json_object_agg_finalfn -	-	-	-				-				-				f f r r 0	2281	0	0		0	_null_ _null_ ));
+DATA(insert ( 3451	n 0 json_objectagg_transfn	json_object_agg_finalfn	-	-	-	-				-				-				f f r r 0	2281	0	0		0	_null_ _null_ ));
 
 /* jsonb */
 DATA(insert ( 3267	n 0 jsonb_agg_transfn	jsonb_agg_finalfn				-	-	-	-				-				-			f f r r 0	2281	0	0		0	_null_ _null_ ));
+DATA(insert ( 6063	n 0 jsonb_agg_strict_transfn	jsonb_agg_finalfn		-	-	-	-				-				-			f f r r 0	2281	0	0		0	_null_ _null_ ));
 DATA(insert ( 3270	n 0 jsonb_object_agg_transfn jsonb_object_agg_finalfn	-	-	-	-				-				-			f f r r 0	2281	0	0		0	_null_ _null_ ));
+DATA(insert ( 6064	n 0 jsonb_objectagg_transfn jsonb_object_agg_finalfn	-	-	-	-				-				-			f f r r 0	2281	0	0		0	_null_ _null_ ));
 
 /* ordered-set and hypothetical-set aggregates */
 DATA(insert ( 3972	o 1 ordered_set_transition			percentile_disc_final					-	-	-	-		-		-		t f s s 0	2281	0	0		0	_null_ _null_ ));
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ee4837b..3a02d9e 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -4549,24 +4549,39 @@ DATA(insert OID = 3156 (  row_to_json	   PGNSP PGUID 12 1 0 0 0 f f f t f s s 2
 DESCR("map row to json with optional pretty printing");
 DATA(insert OID = 3173 (  json_agg_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 2 0 2281 "2281 2283" _null_ _null_ _null_ _null_ _null_ json_agg_transfn _null_ _null_ _null_ ));
 DESCR("json aggregate transition function");
+DATA(insert OID = 3452 (  json_agg_strict_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 2 0 2281 "2281 2283" _null_ _null_ _null_ _null_ _null_ json_agg_strict_transfn _null_ _null_ _null_ ));
+DESCR("json aggregate transition function");
 DATA(insert OID = 3174 (  json_agg_finalfn	 PGNSP PGUID 12 1 0 0 0 f f f f f i s 1 0 114 "2281" _null_ _null_ _null_ _null_ _null_ json_agg_finalfn _null_ _null_ _null_ ));
 DESCR("json aggregate final function");
 DATA(insert OID = 3175 (  json_agg		   PGNSP PGUID 12 1 0 0 0 a f f f f s s 1 0 114 "2283" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
 DESCR("aggregate input into json");
+#define F_JSON_AGG 3175
+DATA(insert OID = 3450 (  json_agg_strict  PGNSP PGUID 12 1 0 0 0 a f f f f s s 1 0 114 "2283" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("aggregate input into json");
+#define F_JSON_AGG_STRICT 3450
 DATA(insert OID = 3180 (  json_object_agg_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 3 0 2281 "2281 2276 2276" _null_ _null_ _null_ _null_ _null_ json_object_agg_transfn _null_ _null_ _null_ ));
 DESCR("json object aggregate transition function");
+DATA(insert OID = 3453 (  json_objectagg_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 5 0 2281 "2281 2276 2276 16 16" _null_ _null_ _null_ _null_ _null_ json_objectagg_transfn _null_ _null_ _null_ ));
+DESCR("json object aggregate transition function");
 DATA(insert OID = 3196 (  json_object_agg_finalfn	 PGNSP PGUID 12 1 0 0 0 f f f f f i s 1 0 114 "2281" _null_ _null_ _null_ _null_ _null_ json_object_agg_finalfn _null_ _null_ _null_ ));
 DESCR("json object aggregate final function");
 DATA(insert OID = 3197 (  json_object_agg		   PGNSP PGUID 12 1 0 0 0 a f f f f s s 2 0 114 "2276 2276" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
 DESCR("aggregate input into a json object");
+DATA(insert OID = 3451 (  json_objectagg		   PGNSP PGUID 12 1 0 0 0 a f f f f s s 4 0 114 "2276 2276 16 16" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("aggregate input into a json object");
+#define F_JSON_OBJECTAGG 3451
 DATA(insert OID = 3198 (  json_build_array	   PGNSP PGUID 12 1 0 2276 0 f f f f f s s 1 0 114 "2276" "{2276}" "{v}" _null_ _null_ _null_ json_build_array _null_ _null_ _null_ ));
 DESCR("build a json array from any inputs");
 DATA(insert OID = 3199 (  json_build_array	   PGNSP PGUID 12 1 0 0 0 f f f f f s s 0 0 114  "" _null_ _null_ _null_ _null_ _null_ json_build_array_noargs _null_ _null_ _null_ ));
 DESCR("build an empty json array");
+DATA(insert OID = 3998 (  json_build_array_ext PGNSP PGUID 12 1 0 2276 0 f f f f f s s 2 0 114 "16 2276" "{16,2276}" "{i,v}" _null_ _null_ _null_ json_build_array_ext _null_ _null_ _null_ ));
+DESCR("build a json array from any inputs");
 DATA(insert OID = 3200 (  json_build_object    PGNSP PGUID 12 1 0 2276 0 f f f f f s s 1 0 114 "2276" "{2276}" "{v}" _null_ _null_ _null_ json_build_object _null_ _null_ _null_ ));
 DESCR("build a json object from pairwise key/value inputs");
 DATA(insert OID = 3201 (  json_build_object    PGNSP PGUID 12 1 0 0 0 f f f f f s s 0 0 114  "" _null_ _null_ _null_ _null_ _null_ json_build_object_noargs _null_ _null_ _null_ ));
 DESCR("build an empty json object");
+DATA(insert OID = 6066 (  json_build_object_ext PGNSP PGUID 12 1 0 2276 0 f f f f f s s 3 0 114 "16 16 2276" "{16,16,2276}" "{i,i,v}" _null_ _null_ _null_ json_build_object_ext _null_ _null_ _null_ ));
+DESCR("build a json object from pairwise key/value inputs");
 DATA(insert OID = 3202 (  json_object	 PGNSP PGUID 12 1 0 0 0 f f f t f i s 1 0 114 "1009" _null_ _null_ _null_ _null_ _null_ json_object _null_ _null_ _null_ ));
 DESCR("map text array of key value pairs to json object");
 DATA(insert OID = 3203 (  json_object	 PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 114 "1009 1009" _null_ _null_ _null_ _null_ _null_ json_object_two_arg _null_ _null_ _null_ ));
@@ -4575,6 +4590,10 @@ DATA(insert OID = 3176 (  to_json	   PGNSP PGUID 12 1 0 0 0 f f f t f s s 1 0 11
 DESCR("map input to json");
 DATA(insert OID = 3261 (  json_strip_nulls	   PGNSP PGUID 12 1 0 0 0 f f f t f i s 1 0 114 "114" _null_ _null_ _null_ _null_ _null_ json_strip_nulls _null_ _null_ _null_ ));
 DESCR("remove object fields with null values from json");
+DATA(insert OID = 6060 (  json_is_valid	       PGNSP PGUID 12 1 0 0 0 f f f t f i s 3 0 16 "114 25 16" _null_ _null_ _null_ _null_ _null_ json_is_valid _null_ _null_ _null_ ));
+DESCR("check json value type and key uniqueness");
+DATA(insert OID = 6061 (  json_is_valid	       PGNSP PGUID 12 1 0 0 0 f f f t f i s 3 0 16 "25 25 16" _null_ _null_ _null_ _null_ _null_ json_is_valid _null_ _null_ _null_ ));
+DESCR("check json text validity, value type and key uniqueness");
 
 DATA(insert OID = 3947 (  json_object_field			PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 114 "114 25" _null_ _null_ "{from_json, field_name}" _null_ _null_ json_object_field _null_ _null_ _null_ ));
 DATA(insert OID = 3948 (  json_object_field_text	PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 25  "114 25" _null_ _null_ "{from_json, field_name}" _null_ _null_ json_object_field_text _null_ _null_ _null_ ));
@@ -5009,26 +5028,44 @@ DATA(insert OID = 3787 (  to_jsonb	   PGNSP PGUID 12 1 0 0 0 f f f t f s s 1 0 3
 DESCR("map input to jsonb");
 DATA(insert OID = 3265 (  jsonb_agg_transfn  PGNSP PGUID 12 1 0 0 0 f f f f f s s 2 0 2281 "2281 2283" _null_ _null_ _null_ _null_ _null_ jsonb_agg_transfn _null_ _null_ _null_ ));
 DESCR("jsonb aggregate transition function");
+DATA(insert OID = 6065 (  jsonb_agg_strict_transfn  PGNSP PGUID 12 1 0 0 0 f f f f f s s 2 0 2281 "2281 2283" _null_ _null_ _null_ _null_ _null_ jsonb_agg_strict_transfn _null_ _null_ _null_ ));
+DESCR("jsonb aggregate transition function");
 DATA(insert OID = 3266 (  jsonb_agg_finalfn  PGNSP PGUID 12 1 0 0 0 f f f f f s s 1 0 3802 "2281" _null_ _null_ _null_ _null_ _null_ jsonb_agg_finalfn _null_ _null_ _null_ ));
 DESCR("jsonb aggregate final function");
 DATA(insert OID = 3267 (  jsonb_agg		   PGNSP PGUID 12 1 0 0 0 a f f f f s s 1 0 3802 "2283" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
 DESCR("aggregate input into jsonb");
+#define F_JSONB_AGG 3267
+DATA(insert OID = 6063 (  jsonb_agg_strict PGNSP PGUID 12 1 0 0 0 a f f f f s s 1 0 3802 "2283" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("aggregate input into jsonb skipping nulls");
+#define F_JSONB_AGG_STRICT 6063
 DATA(insert OID = 3268 (  jsonb_object_agg_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 3 0 2281 "2281 2276 2276" _null_ _null_ _null_ _null_ _null_ jsonb_object_agg_transfn _null_ _null_ _null_ ));
 DESCR("jsonb object aggregate transition function");
+DATA(insert OID = 3449 (  jsonb_objectagg_transfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 5 0 2281 "2281 2276 2276 16 16" _null_ _null_ _null_ _null_ _null_ jsonb_objectagg_transfn _null_ _null_ _null_ ));
+DESCR("jsonb object aggregate transition function");
 DATA(insert OID = 3269 (  jsonb_object_agg_finalfn	 PGNSP PGUID 12 1 0 0 0 f f f f f s s 1 0 3802 "2281" _null_ _null_ _null_ _null_ _null_ jsonb_object_agg_finalfn _null_ _null_ _null_ ));
 DESCR("jsonb object aggregate final function");
 DATA(insert OID = 3270 (  jsonb_object_agg		   PGNSP PGUID 12 1 0 0 0 a f f f f i s 2 0 3802 "2276 2276" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
 DESCR("aggregate inputs into jsonb object");
+DATA(insert OID = 6064 (  jsonb_objectagg		   PGNSP PGUID 12 1 0 0 0 a f f f f i s 4 0 3802 "2276 2276 16 16" _null_ _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("aggregate inputs into jsonb object");
+#define F_JSONB_OBJECTAGG 6064
 DATA(insert OID = 3271 (  jsonb_build_array    PGNSP PGUID 12 1 0 2276 0 f f f f f s s 1 0 3802 "2276" "{2276}" "{v}" _null_ _null_ _null_ jsonb_build_array _null_ _null_ _null_ ));
 DESCR("build a jsonb array from any inputs");
 DATA(insert OID = 3272 (  jsonb_build_array    PGNSP PGUID 12 1 0 0 0 f f f f f s s 0 0 3802	"" _null_ _null_ _null_ _null_ _null_ jsonb_build_array_noargs _null_ _null_ _null_ ));
 DESCR("build an empty jsonb array");
+DATA(insert OID = 6068 (  jsonb_build_array_ext PGNSP PGUID 12 1 0 2276 0 f f f f f s s 2 0 3802 "16 2276" "{16,2276}" "{i,v}" _null_ _null_ _null_ jsonb_build_array_ext _null_ _null_ _null_ ));
+DESCR("build a jsonb array from any inputs");
 DATA(insert OID = 3273 (  jsonb_build_object	PGNSP PGUID 12 1 0 2276 0 f f f f f s s 1 0 3802 "2276" "{2276}" "{v}" _null_ _null_ _null_ jsonb_build_object _null_ _null_ _null_ ));
 DESCR("build a jsonb object from pairwise key/value inputs");
 DATA(insert OID = 3274 (  jsonb_build_object	PGNSP PGUID 12 1 0 0 0 f f f f f s s 0 0 3802  "" _null_ _null_ _null_ _null_ _null_ jsonb_build_object_noargs _null_ _null_ _null_ ));
 DESCR("build an empty jsonb object");
+DATA(insert OID = 6067 (  jsonb_build_object_ext PGNSP PGUID 12 1 0 2276 0 f f f f f s s 3 0 3802 "16 16 2276" "{16,16,2276}" "{i,i,v}" _null_ _null_ _null_ jsonb_build_object_ext _null_ _null_ _null_ ));
+DESCR("build a jsonb object from pairwise key/value inputs");
 DATA(insert OID = 3262 (  jsonb_strip_nulls    PGNSP PGUID 12 1 0 0 0 f f f t f i s 1 0 3802 "3802" _null_ _null_ _null_ _null_ _null_ jsonb_strip_nulls _null_ _null_ _null_ ));
 DESCR("remove object fields with null values from jsonb");
+DATA(insert OID = 6062 (  jsonb_is_valid	   PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 16 "17 25" _null_ _null_ _null_ _null_ _null_ jsonb_is_valid _null_ _null_ _null_ ));
+DESCR("check jsonb value type");
+
 
 DATA(insert OID = 3478 (  jsonb_object_field			PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 3802 "3802 25" _null_ _null_ "{from_json, field_name}" _null_ _null_ jsonb_object_field _null_ _null_ _null_ ));
 DATA(insert OID = 3214 (  jsonb_object_field_text	PGNSP PGUID 12 1 0 0 0 f f f t f i s 2 0 25  "3802 25" _null_ _null_ "{from_json, field_name}" _null_ _null_ jsonb_object_field_text _null_ _null_ _null_ ));
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 0cab431..1e0ee9b 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -20,6 +20,7 @@
 /* forward references to avoid circularity */
 struct ExprEvalStep;
 struct ArrayRefState;
+struct JsonbValue;
 
 /* Bits in ExprState->flags (see also execnodes.h for public flag bits): */
 /* expression's interpreter has been initialized */
@@ -219,6 +220,7 @@ typedef enum ExprEvalOp
 	EEOP_WINDOW_FUNC,
 	EEOP_SUBPLAN,
 	EEOP_ALTERNATIVE_SUBPLAN,
+	EEOP_JSONEXPR,
 
 	/* aggregation related nodes */
 	EEOP_AGG_STRICT_DESERIALIZE,
@@ -635,6 +637,54 @@ typedef struct ExprEvalStep
 			int			transno;
 			int			setoff;
 		}			agg_trans;
+
+		/* for EEOP_JSONEXPR */
+		struct
+		{
+			JsonExpr   *jsexpr;			/* original expression node */
+			char		volatility;		/* volatility of subexpressions */
+
+			struct
+			{
+				FmgrInfo	func;		/* typinput function for output type */
+				Oid			typioparam;
+			} input;					/* I/O info for output type */
+
+			struct
+			{
+				Datum		value;
+				bool		isnull;
+			}		   *raw_expr,			/* raw context item value */
+					   *pathspec;			/* path specification value */
+
+			ExprState  *formatted_expr;		/* formatted context item */
+			ExprState  *result_expr;		/* coerced to output type */
+			ExprState  *default_on_empty;	/* ON EMPTY DEFAULT expression */
+			ExprState  *default_on_error;	/* ON ERROR DEFAULT expression */
+			List	   *args;				/* passing arguments */
+
+			void	   *cache;				/* cache for json_populate_type() */
+
+			struct JsonCoercionsState
+			{
+				struct JsonCoercionState
+				{
+					JsonCoercion *coercion;		/* coercion expression */
+					ExprState  *estate;	/* coercion expression state */
+				} 			null,
+							string,
+							numeric,
+							boolean,
+							date,
+							time,
+							timetz,
+							timestamp,
+							timestamptz,
+							composite;
+			}			coercions;	/* states for coercion from SQL/JSON item
+									 * types directly to the output type */
+		}			jsonexpr;
+
 	}			d;
 } ExprEvalStep;
 
@@ -730,6 +780,12 @@ extern void ExecEvalAlternativeSubPlan(ExprState *state, ExprEvalStep *op,
 						   ExprContext *econtext);
 extern void ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op,
 					ExprContext *econtext);
+extern void ExecEvalJson(ExprState *state, ExprEvalStep *op,
+						 ExprContext *econtext);
+extern Datum ExecPrepareJsonItemCoercion(struct JsonbValue *item,
+							JsonReturning *returning,
+							struct JsonCoercionsState *coercions,
+							struct JsonCoercionState **pjcstate);
 
 extern void ExecAggInitGroup(AggState *aggstate, AggStatePerTrans pertrans, AggStatePerGroup pergroup);
 extern Datum ExecAggTransReparent(AggState *aggstate, AggStatePerTrans pertrans,
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 57bd52f..f7aec03 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -88,4 +88,11 @@ extern GroupingSet *makeGroupingSet(GroupingSetKind kind, List *content, int loc
 
 extern VacuumRelation *makeVacuumRelation(RangeVar *relation, Oid oid, List *va_cols);
 
+extern JsonValueExpr *makeJsonValueExpr(Expr *expr, JsonFormat format);
+extern JsonBehavior *makeJsonBehavior(JsonBehaviorType type, Node *expr);
+extern Node *makeJsonKeyValue(Node *key, Node *value);
+extern Node *makeJsonIsPredicate(Node *expr, JsonFormat format,
+							   JsonValueType vtype, bool unique_keys);
+extern JsonEncoding makeJsonEncoding(char *name);
+
 #endif							/* MAKEFUNC_H */
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 74b094a..14c387a 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -191,6 +191,9 @@ typedef enum NodeTag
 	T_FromExpr,
 	T_OnConflictExpr,
 	T_IntoClause,
+	T_JsonExpr,
+	T_JsonCoercion,
+	T_JsonItemCoercions,
 
 	/*
 	 * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
@@ -471,6 +474,22 @@ typedef enum NodeTag
 	T_PartitionRangeDatum,
 	T_PartitionCmd,
 	T_VacuumRelation,
+	T_JsonValueExpr,
+	T_JsonObjectCtor,
+	T_JsonArrayCtor,
+	T_JsonArrayQueryCtor,
+	T_JsonObjectAgg,
+	T_JsonArrayAgg,
+	T_JsonFuncExpr,
+	T_JsonIsPredicate,
+	T_JsonExistsPredicate,
+	T_JsonCommon,
+	T_JsonArgument,
+	T_JsonKeyValue,
+	T_JsonBehavior,
+	T_JsonOutput,
+	T_JsonCtorOpts,
+	T_JsonIsPredicateOpts,
 
 	/*
 	 * TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index f668cba..5c2585e 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1426,6 +1426,221 @@ typedef struct TriggerTransition
 	bool		isTable;
 } TriggerTransition;
 
+/* Nodes for SQL/JSON support */
+
+/*
+ * JsonQuotes -
+ *		representation of [KEEP|OMIT] QUOTES clause for JSON_QUERY()
+ */
+typedef enum JsonQuotes
+{
+	JS_QUOTES_UNSPEC,			/* unspecified */
+	JS_QUOTES_KEEP,				/* KEEP QUOTES */
+	JS_QUOTES_OMIT				/* OMIT QUOTES */
+} JsonQuotes;
+
+/*
+ * JsonPathSpec -
+ *		representation of JSON path constant
+ */
+typedef char *JsonPathSpec;
+
+/*
+ * JsonOutput -
+ *		representation of JSON output clause (RETURNING type [FORMAT format])
+ */
+typedef struct JsonOutput
+{
+	NodeTag		type;
+	TypeName   *typename;		/* RETURNING type name, if specified */
+	JsonReturning returning;	/* RETURNING FORMAT clause and type Oids */
+} JsonOutput;
+
+/*
+ * JsonValueExpr -
+ *		representation of JSON value expression (expr [FORMAT json_format])
+ */
+typedef struct JsonValueExpr
+{
+	NodeTag		type;
+	Expr	   *expr;			/* raw expression */
+	JsonFormat  format;			/* FORMAT clause, if specified */
+} JsonValueExpr;
+
+/*
+ * JsonArgument -
+ *		representation of argument from JSON PASSING clause
+ */
+typedef struct JsonArgument
+{
+	NodeTag		type;
+	JsonValueExpr *val;			/* argument value expression */
+	char	   *name;			/* argument name */
+} JsonArgument;
+
+/*
+ * JsonCommon -
+ *		representation of common syntax of functions using JSON path
+ */
+typedef struct JsonCommon
+{
+	NodeTag		type;
+	JsonValueExpr *expr;		/* context item expression */
+	Node	   *pathspec;		/* JSON path specification expression */
+	char	   *pathname;		/* path name, if any */
+	List	   *passing;		/* list of PASSING clause arguments, if any */
+	int			location;		/* token location, or -1 if unknown */
+} JsonCommon;
+
+/*
+ * JsonFuncExpr -
+ *		untransformed representation of JSON function expressions
+ */
+typedef struct JsonFuncExpr
+{
+	NodeTag		type;
+	JsonExprOp	op;				/* expression type */
+	JsonCommon *common;			/* common syntax */
+	JsonOutput *output;			/* output clause, if specified */
+	JsonBehavior *on_empty;		/* ON EMPTY behavior, if specified */
+	JsonBehavior *on_error;		/* ON ERROR behavior, if specified */
+	JsonWrapper	wrapper;		/* array wrapper behavior (JSON_QUERY only) */
+	bool		omit_quotes;	/* omit or keep quotes? (JSON_QUERY only) */
+	int			location;		/* token location, or -1 if unknown */
+} JsonFuncExpr;
+
+/*
+ * JsonValueType -
+ *		representation of JSON item type in IS JSON predicate
+ */
+typedef enum JsonValueType
+{
+	JS_TYPE_ANY,				/* IS JSON [VALUE] */
+	JS_TYPE_OBJECT,				/* IS JSON OBJECT */
+	JS_TYPE_ARRAY,				/* IS JSON ARRAY*/
+	JS_TYPE_SCALAR				/* IS JSON SCALAR */
+} JsonValueType;
+
+/*
+ * JsonIsPredicate -
+ *		untransformed representation of IS JSON predicate
+ */
+typedef struct JsonIsPredicate
+{
+	NodeTag		type;
+	Node	   *expr;			/* untransformed expression */
+	JsonFormat	format;			/* FORMAT clause, if specified */
+	JsonValueType vtype;		/* JSON item type */
+	bool		unique_keys;	/* check key uniqueness? */
+	int			location;		/* token location, or -1 if unknown */
+} JsonIsPredicate;
+
+typedef struct JsonIsPredicateOpts
+{
+	NodeTag		type;
+	JsonValueType value_type;	/* JSON item type */
+	bool		unique_keys;	/* check key uniqueness? */
+} JsonIsPredicateOpts;
+
+/*
+ * JsonKeyValue -
+ *		untransformed representation of JSON object key-value pair for
+ *		JSON_OBJECT() and JSON_OBJECTAGG()
+ */
+typedef struct JsonKeyValue
+{
+	NodeTag		type;
+	Expr	   *key;			/* key expression */
+	JsonValueExpr *value;		/* JSON value expression */
+} JsonKeyValue;
+
+/*
+ * JsonObjectCtor -
+ *		untransformed representation of JSON_OBJECT() constructor
+ */
+typedef struct JsonObjectCtor
+{
+	NodeTag		type;
+	List	   *exprs;			/* list of JsonKeyValue pairs */
+	JsonOutput *output;			/* RETURNING clause, if specified  */
+	bool		absent_on_null;	/* skip NULL values? */
+	bool		unique;			/* check key uniqueness? */
+	int			location;		/* token location, or -1 if unknown */
+} JsonObjectCtor;
+
+/*
+ * JsonArrayCtor -
+ *		untransformed representation of JSON_ARRAY(element,...) constructor
+ */
+typedef struct JsonArrayCtor
+{
+	NodeTag		type;
+	List	   *exprs;			/* list of JsonValueExpr elements */
+	JsonOutput *output;			/* RETURNING clause, if specified  */
+	bool		absent_on_null;	/* skip NULL elements? */
+	int			location;		/* token location, or -1 if unknown */
+} JsonArrayCtor;
+
+/*
+ * JsonArrayQueryCtor -
+ *		untransformed representation of JSON_ARRAY(subquery) constructor
+ */
+typedef struct JsonArrayQueryCtor
+{
+	NodeTag		type;
+	Node	   *query;			/* subquery */
+	JsonOutput *output;			/* RETURNING clause, if specified  */
+	JsonFormat	format;			/* FORMAT clause for subquery, if specified */
+	bool		absent_on_null;	/* skip NULL elements? */
+	int			location;		/* token location, or -1 if unknown */
+} JsonArrayQueryCtor;
+
+/*
+ * JsonAggCtor -
+ *		common fields of untransformed representation of
+ *		JSON_ARRAYAGG() and JSON_OBJECTAGG()
+ */
+typedef struct JsonAggCtor
+{
+	NodeTag		type;
+	JsonOutput *output;			/* RETURNING clause, if any */
+	Node	   *agg_filter;		/* FILTER clause, if any */
+	List	   *agg_order;		/* ORDER BY clause, if any */
+	struct WindowDef *over;		/* OVER clause, if any */
+	int			location;		/* token location, or -1 if unknown */
+} JsonAggCtor;
+
+/*
+ * JsonObjectAgg -
+ *		untransformed representation of JSON_OBJECTAGG()
+ */
+typedef struct JsonObjectAgg
+{
+	JsonAggCtor	ctor;			/* common fields */
+	JsonKeyValue *arg;			/* object key-value pair */
+	bool		absent_on_null;	/* skip NULL values? */
+	bool		unique;			/* check key uniqueness? */
+} JsonObjectAgg;
+
+/*
+ * JsonArrayAgg -
+ *		untransformed representation of JSON_ARRRAYAGG()
+ */
+typedef struct JsonArrayAgg
+{
+	JsonAggCtor	ctor;			/* common fields */
+	JsonValueExpr *arg;			/* array element expression */
+	bool		absent_on_null;	/* skip NULL elements? */
+} JsonArrayAgg;
+
+typedef struct JsonCtorOpts
+{
+	NodeTag		type;
+	JsonReturning returning;	/* RETURNING clause */
+	bool		absent_on_null;	/* skip NULL values? */
+	bool		unique;			/* check key uniqueness? */
+} JsonCtorOpts;
+
 /*****************************************************************************
  *		Raw Grammar Output Statements
  *****************************************************************************/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 641500e..4bfa016 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -252,6 +252,11 @@ typedef struct Param
 typedef enum FuncFormat
 {
 	FUNCFMT_REGULAR = 0,
+	FUNCFMT_JSON_OBJECT = 1,
+	FUNCFMT_JSON_ARRAY = 2,
+	FUNCFMT_JSON_OBJECTAGG = 3,
+	FUNCFMT_JSON_ARRAYAGG = 4,
+	FUNCFMT_IS_JSON = 5
 } FuncFormat;
 
 /*
@@ -1169,6 +1174,167 @@ typedef struct XmlExpr
 	int			location;		/* token location, or -1 if unknown */
 } XmlExpr;
 
+/*
+ * JsonExprOp -
+ *		enumeration of JSON functions using JSON path
+ */
+typedef enum JsonExprOp
+{
+	IS_JSON_VALUE,				/* JSON_VALUE() */
+	IS_JSON_QUERY,				/* JSON_QUERY() */
+	IS_JSON_EXISTS				/* JSON_EXISTS() */
+} JsonExprOp;
+
+/*
+ * JsonEncoding -
+ *		representation of JSON ENCODING clause
+ */
+typedef enum JsonEncoding
+{
+	JS_ENC_DEFAULT,				/* unspecified */
+	JS_ENC_UTF8,
+	JS_ENC_UTF16,
+	JS_ENC_UTF32,
+} JsonEncoding;
+
+/*
+ * JsonFormatType -
+ *		enumeration of JSON formats used in JSON FORMAT clause
+ */
+typedef enum JsonFormatType
+{
+	JS_FORMAT_DEFAULT,			/* unspecified */
+	JS_FORMAT_JSON,				/* FORMAT JSON [ENCODING ...] */
+	JS_FORMAT_JSONB				/* implicit internal format for RETURNING jsonb */
+} JsonFormatType;
+
+/*
+ * JsonBehaviorType -
+ *		enumeration of behavior types used in JSON ON ... BEHAVIOR clause
+ */
+typedef enum
+{
+	JSON_BEHAVIOR_NULL,
+	JSON_BEHAVIOR_ERROR,
+	JSON_BEHAVIOR_EMPTY,
+	JSON_BEHAVIOR_TRUE,
+	JSON_BEHAVIOR_FALSE,
+	JSON_BEHAVIOR_UNKNOWN,
+	JSON_BEHAVIOR_EMPTY_ARRAY,
+	JSON_BEHAVIOR_EMPTY_OBJECT,
+	JSON_BEHAVIOR_DEFAULT,
+} JsonBehaviorType;
+
+/*
+ * JsonWrapper -
+ *		representation of WRAPPER clause for JSON_QUERY()
+ */
+typedef enum JsonWrapper
+{
+	JSW_NONE,
+	JSW_CONDITIONAL,
+	JSW_UNCONDITIONAL,
+} JsonWrapper;
+
+/*
+ * JsonFormat -
+ *		representation of JSON FORMAT clause
+ */
+typedef struct JsonFormat
+{
+	JsonFormatType	type;		/* format type */
+	JsonEncoding	encoding;	/* JSON encoding */
+	int				location;	/* token location, or -1 if unknown */
+} JsonFormat;
+
+/*
+ * JsonReturning -
+ *		transformed representation of JSON RETURNING clause
+ */
+typedef struct JsonReturning
+{
+	JsonFormat	format;			/* output JSON format */
+	Oid			typid;			/* target type Oid */
+	int32		typmod;			/* target type modifier */
+} JsonReturning;
+
+/*
+ * JsonBehavior -
+ *		representation of JSON ON ... BEHAVIOR clause
+ */
+typedef struct JsonBehavior
+{
+	NodeTag		type;
+	JsonBehaviorType btype;		/* behavior type */
+	Node	   *default_expr;	/* default expression, if any */
+} JsonBehavior;
+
+/*
+ * JsonPassing -
+ *		representation of JSON PASSING clause
+ */
+typedef struct JsonPassing
+{
+	List	   *values;			/* list of PASSING argument expressions */
+	List	   *names;			/* parallel list of Value strings */
+} JsonPassing;
+
+/*
+ * JsonCoercion -
+ *		coercion from SQL/JSON item types to SQL types
+ */
+typedef struct JsonCoercion
+{
+	NodeTag		type;
+	Node	   *expr;			/* resulting expression coerced to target type */
+	bool		via_populate;	/* coerce result using json_populate_type()? */
+	bool		via_io;			/* coerce result using type input function? */
+	Oid			collation;		/* collation for coercion via I/O or populate */
+} JsonCoercion;
+
+/*
+ * JsonItemCoercions -
+ *		expressions for coercion from SQL/JSON item types directly to the
+ *		output SQL type
+ */
+typedef struct JsonItemCoercions
+{
+	NodeTag		type;
+	JsonCoercion *null;
+	JsonCoercion *string;
+	JsonCoercion *numeric;
+	JsonCoercion *boolean;
+	JsonCoercion *date;
+	JsonCoercion *time;
+	JsonCoercion *timetz;
+	JsonCoercion *timestamp;
+	JsonCoercion *timestamptz;
+	JsonCoercion *composite;	/* arrays and objects */
+} JsonItemCoercions;
+
+/*
+ * JsonExpr -
+ *		transformed representation of JSON_VALUE(), JSON_QUERY(), JSON_EXISTS()
+ */
+typedef struct JsonExpr
+{
+	Expr		xpr;
+	JsonExprOp	op;				/* json function ID */
+	Node	   *raw_expr;		/* raw context item expression */
+	Node	   *formatted_expr;	/* formatted context item expression */
+	JsonCoercion *result_coercion;	/* resulting coercion to RETURNING type */
+	JsonFormat	format;			/* context item format (JSON/JSONB) */
+	Node	   *path_spec;		/* JSON path specification expression */
+	JsonPassing	passing;		/* PASSING clause arguments */
+	JsonReturning returning;	/* RETURNING clause type/format info */
+	JsonBehavior on_empty;		/* ON EMPTY behavior */
+	JsonBehavior on_error;		/* ON ERROR behavior */
+	JsonItemCoercions *coercions; /* coercions for JSON_VALUE */
+	JsonWrapper	wrapper;		/* WRAPPER for JSON_QUERY */
+	bool		omit_quotes;	/* KEEP/OMIT QUOTES for JSON_QUERY */
+	int			location;		/* token location, or -1 if unknown */
+} JsonExpr;
+
 /* ----------------
  * NullTest
  *
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index cf32197..233e18d 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -27,6 +27,7 @@
 
 /* name, value, category */
 PG_KEYWORD("abort", ABORT_P, UNRESERVED_KEYWORD)
+PG_KEYWORD("absent", ABSENT, UNRESERVED_KEYWORD)
 PG_KEYWORD("absolute", ABSOLUTE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("access", ACCESS, UNRESERVED_KEYWORD)
 PG_KEYWORD("action", ACTION, UNRESERVED_KEYWORD)
@@ -89,6 +90,7 @@ PG_KEYWORD("comments", COMMENTS, UNRESERVED_KEYWORD)
 PG_KEYWORD("commit", COMMIT, UNRESERVED_KEYWORD)
 PG_KEYWORD("committed", COMMITTED, UNRESERVED_KEYWORD)
 PG_KEYWORD("concurrently", CONCURRENTLY, TYPE_FUNC_NAME_KEYWORD)
+PG_KEYWORD("conditional", CONDITIONAL, UNRESERVED_KEYWORD)
 PG_KEYWORD("configuration", CONFIGURATION, UNRESERVED_KEYWORD)
 PG_KEYWORD("conflict", CONFLICT, UNRESERVED_KEYWORD)
 PG_KEYWORD("connection", CONNECTION, UNRESERVED_KEYWORD)
@@ -142,11 +144,13 @@ PG_KEYWORD("double", DOUBLE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("drop", DROP, UNRESERVED_KEYWORD)
 PG_KEYWORD("each", EACH, UNRESERVED_KEYWORD)
 PG_KEYWORD("else", ELSE, RESERVED_KEYWORD)
+PG_KEYWORD("empty", EMPTY_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("enable", ENABLE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("encoding", ENCODING, UNRESERVED_KEYWORD)
 PG_KEYWORD("encrypted", ENCRYPTED, UNRESERVED_KEYWORD)
 PG_KEYWORD("end", END_P, RESERVED_KEYWORD)
 PG_KEYWORD("enum", ENUM_P, UNRESERVED_KEYWORD)
+PG_KEYWORD("error", ERROR_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("escape", ESCAPE, UNRESERVED_KEYWORD)
 PG_KEYWORD("event", EVENT, UNRESERVED_KEYWORD)
 PG_KEYWORD("except", EXCEPT, RESERVED_KEYWORD)
@@ -169,6 +173,7 @@ PG_KEYWORD("following", FOLLOWING, UNRESERVED_KEYWORD)
 PG_KEYWORD("for", FOR, RESERVED_KEYWORD)
 PG_KEYWORD("force", FORCE, UNRESERVED_KEYWORD)
 PG_KEYWORD("foreign", FOREIGN, RESERVED_KEYWORD)
+PG_KEYWORD("format", FORMAT, TYPE_FUNC_NAME_KEYWORD)
 PG_KEYWORD("forward", FORWARD, UNRESERVED_KEYWORD)
 PG_KEYWORD("freeze", FREEZE, TYPE_FUNC_NAME_KEYWORD)
 PG_KEYWORD("from", FROM, RESERVED_KEYWORD)
@@ -220,7 +225,17 @@ PG_KEYWORD("is", IS, TYPE_FUNC_NAME_KEYWORD)
 PG_KEYWORD("isnull", ISNULL, TYPE_FUNC_NAME_KEYWORD)
 PG_KEYWORD("isolation", ISOLATION, UNRESERVED_KEYWORD)
 PG_KEYWORD("join", JOIN, TYPE_FUNC_NAME_KEYWORD)
+PG_KEYWORD("json", JSON, UNRESERVED_KEYWORD)
+PG_KEYWORD("json_array", JSON_ARRAY, COL_NAME_KEYWORD)
+PG_KEYWORD("json_arrayagg", JSON_ARRAYAGG, COL_NAME_KEYWORD)
+PG_KEYWORD("json_exists", JSON_EXISTS, COL_NAME_KEYWORD)
+PG_KEYWORD("json_object", JSON_OBJECT, COL_NAME_KEYWORD)
+PG_KEYWORD("json_objectagg", JSON_OBJECTAGG, COL_NAME_KEYWORD)
+PG_KEYWORD("json_query", JSON_QUERY, COL_NAME_KEYWORD)
+PG_KEYWORD("json_value", JSON_VALUE, COL_NAME_KEYWORD)
+PG_KEYWORD("keep", KEEP, UNRESERVED_KEYWORD)
 PG_KEYWORD("key", KEY, UNRESERVED_KEYWORD)
+PG_KEYWORD("keys", KEYS, UNRESERVED_KEYWORD)
 PG_KEYWORD("label", LABEL, UNRESERVED_KEYWORD)
 PG_KEYWORD("language", LANGUAGE, UNRESERVED_KEYWORD)
 PG_KEYWORD("large", LARGE_P, UNRESERVED_KEYWORD)
@@ -276,6 +291,7 @@ PG_KEYWORD("off", OFF, UNRESERVED_KEYWORD)
 PG_KEYWORD("offset", OFFSET, RESERVED_KEYWORD)
 PG_KEYWORD("oids", OIDS, UNRESERVED_KEYWORD)
 PG_KEYWORD("old", OLD, UNRESERVED_KEYWORD)
+PG_KEYWORD("omit", OMIT, UNRESERVED_KEYWORD)
 PG_KEYWORD("on", ON, RESERVED_KEYWORD)
 PG_KEYWORD("only", ONLY, RESERVED_KEYWORD)
 PG_KEYWORD("operator", OPERATOR, UNRESERVED_KEYWORD)
@@ -317,6 +333,7 @@ PG_KEYWORD("procedures", PROCEDURES, UNRESERVED_KEYWORD)
 PG_KEYWORD("program", PROGRAM, UNRESERVED_KEYWORD)
 PG_KEYWORD("publication", PUBLICATION, UNRESERVED_KEYWORD)
 PG_KEYWORD("quote", QUOTE, UNRESERVED_KEYWORD)
+PG_KEYWORD("quotes", QUOTES, UNRESERVED_KEYWORD)
 PG_KEYWORD("range", RANGE, UNRESERVED_KEYWORD)
 PG_KEYWORD("read", READ, UNRESERVED_KEYWORD)
 PG_KEYWORD("real", REAL, COL_NAME_KEYWORD)
@@ -350,6 +367,7 @@ PG_KEYWORD("row", ROW, COL_NAME_KEYWORD)
 PG_KEYWORD("rows", ROWS, UNRESERVED_KEYWORD)
 PG_KEYWORD("rule", RULE, UNRESERVED_KEYWORD)
 PG_KEYWORD("savepoint", SAVEPOINT, UNRESERVED_KEYWORD)
+PG_KEYWORD("scalar", SCALAR, UNRESERVED_KEYWORD)
 PG_KEYWORD("schema", SCHEMA, UNRESERVED_KEYWORD)
 PG_KEYWORD("schemas", SCHEMAS, UNRESERVED_KEYWORD)
 PG_KEYWORD("scroll", SCROLL, UNRESERVED_KEYWORD)
@@ -384,6 +402,7 @@ PG_KEYWORD("stdin", STDIN, UNRESERVED_KEYWORD)
 PG_KEYWORD("stdout", STDOUT, UNRESERVED_KEYWORD)
 PG_KEYWORD("storage", STORAGE, UNRESERVED_KEYWORD)
 PG_KEYWORD("strict", STRICT_P, UNRESERVED_KEYWORD)
+PG_KEYWORD("string", STRING, COL_NAME_KEYWORD)
 PG_KEYWORD("strip", STRIP_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("subscription", SUBSCRIPTION, UNRESERVED_KEYWORD)
 PG_KEYWORD("substring", SUBSTRING, COL_NAME_KEYWORD)
@@ -416,6 +435,7 @@ PG_KEYWORD("type", TYPE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("types", TYPES_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("unbounded", UNBOUNDED, UNRESERVED_KEYWORD)
 PG_KEYWORD("uncommitted", UNCOMMITTED, UNRESERVED_KEYWORD)
+PG_KEYWORD("unconditional", UNCONDITIONAL, UNRESERVED_KEYWORD)
 PG_KEYWORD("unencrypted", UNENCRYPTED, UNRESERVED_KEYWORD)
 PG_KEYWORD("union", UNION, RESERVED_KEYWORD)
 PG_KEYWORD("unique", UNIQUE, RESERVED_KEYWORD)
diff --git a/src/include/utils/jsonapi.h b/src/include/utils/jsonapi.h
index 67c3031..0c86bf8 100644
--- a/src/include/utils/jsonapi.h
+++ b/src/include/utils/jsonapi.h
@@ -192,6 +192,10 @@ extern text *transform_json_string_values(text *json, void *action_state,
 
 extern char *JsonEncodeDateTime(char *buf, Datum value, Oid typid, int *tz);
 
+extern Datum json_populate_type(Datum json_val, Oid json_type,
+								Oid typid, int32 typmod,
+								void **cache, MemoryContext mcxt, bool *isnull);
+
 extern Json *JsonCreate(text *json);
 extern JsonbIteratorToken JsonIteratorNext(JsonIterator **pit, JsonbValue *val,
 				 bool skipNested);
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 2ea1ec1..d312b6c 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -401,6 +401,9 @@ extern char *JsonbToCString(StringInfo out, JsonbContainer *in,
 extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 					 int estimated_len);
 
+extern Jsonb *JsonbMakeEmptyArray(void);
+extern Jsonb *JsonbMakeEmptyObject(void);
+extern char *JsonbUnquote(Jsonb *jb);
 extern JsonbValue *JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h
index 87dae0d..61cf2b7 100644
--- a/src/include/utils/jsonpath.h
+++ b/src/include/utils/jsonpath.h
@@ -17,6 +17,7 @@
 #include "fmgr.h"
 #include "utils/jsonb.h"
 #include "nodes/pg_list.h"
+#include "nodes/primnodes.h"
 
 typedef struct
 {
@@ -256,7 +257,15 @@ typedef struct JsonPathVariable	{
 	void					*cb_arg;
 } JsonPathVariable;
 
-
+typedef struct JsonPathVariableEvalContext
+{
+	JsonPathVariable var;
+	struct ExprContext *econtext;
+	struct ExprState  *estate;
+	Datum		value;
+	bool		isnull;
+	bool		evaluated;
+} JsonPathVariableEvalContext;
 
 typedef struct JsonValueList
 {
@@ -269,4 +278,12 @@ JsonPathExecResult	executeJsonPath(JsonPath *path,
 									Jsonb *json,
 									JsonValueList *foundJson);
 
+extern bool  JsonbPathExists(Datum jb, JsonPath *path, List *vars);
+extern Datum JsonbPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper,
+			   bool *empty, List *vars);
+extern JsonbValue *JsonbPathValue(Datum jb, JsonPath *jp, bool *empty,
+			   List *vars);
+
+extern Datum EvalJsonPathVar(void *cxt, bool *isnull);
+
 #endif
diff --git a/src/interfaces/ecpg/preproc/parse.pl b/src/interfaces/ecpg/preproc/parse.pl
index e68cc26..529a5b7 100644
--- a/src/interfaces/ecpg/preproc/parse.pl
+++ b/src/interfaces/ecpg/preproc/parse.pl
@@ -45,6 +45,8 @@ my %replace_string = (
 	'NOT_LA'         => 'not',
 	'NULLS_LA'       => 'nulls',
 	'WITH_LA'        => 'with',
+	'WITH_LA_UNIQUE' => 'with',
+	'WITHOUT_LA'     => 'without',
 	'TYPECAST'       => '::',
 	'DOT_DOT'        => '..',
 	'COLON_EQUALS'   => ':=',
diff --git a/src/interfaces/ecpg/preproc/parser.c b/src/interfaces/ecpg/preproc/parser.c
index e5a8f9d..e576202 100644
--- a/src/interfaces/ecpg/preproc/parser.c
+++ b/src/interfaces/ecpg/preproc/parser.c
@@ -84,6 +84,9 @@ filtered_base_yylex(void)
 		case WITH:
 			cur_token_length = 4;
 			break;
+		case WITHOUT:
+			cur_token_length = 7;
+			break;
 		default:
 			return cur_token;
 	}
@@ -155,8 +158,22 @@ filtered_base_yylex(void)
 				case ORDINALITY:
 					cur_token = WITH_LA;
 					break;
+				case UNIQUE:
+					cur_token = WITH_LA_UNIQUE;
+					break;
+			}
+			break;
+
+		case WITHOUT:
+			/* Replace WITHOUT by WITHOUT_LA if it's followed by TIME */
+			switch (next_token)
+			{
+				case TIME:
+					cur_token = WITHOUT_LA;
+					break;
 			}
 			break;
+
 	}
 
 	return cur_token;
diff --git a/src/test/regress/expected/json_sqljson.out b/src/test/regress/expected/json_sqljson.out
new file mode 100644
index 0000000..bb62634
--- /dev/null
+++ b/src/test/regress/expected/json_sqljson.out
@@ -0,0 +1,15 @@
+-- JSON_EXISTS
+SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+ERROR:  JSON_EXISTS() is not yet implemented for json type
+LINE 1: SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+               ^
+-- JSON_VALUE
+SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+ERROR:  JSON_VALUE() is not yet implemented for json type
+LINE 1: SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+               ^
+-- JSON_QUERY
+SELECT JSON_QUERY(NULL FORMAT JSON, '$');
+ERROR:  JSON_QUERY() is not yet implemented for json type
+LINE 1: SELECT JSON_QUERY(NULL FORMAT JSON, '$');
+               ^
diff --git a/src/test/regress/expected/jsonb_sqljson.out b/src/test/regress/expected/jsonb_sqljson.out
new file mode 100644
index 0000000..28c82a1
--- /dev/null
+++ b/src/test/regress/expected/jsonb_sqljson.out
@@ -0,0 +1,955 @@
+-- JSON_EXISTS
+SELECT JSON_EXISTS(NULL::jsonb, '$');
+ json_exists 
+-------------
+ 
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(JSON_OBJECT(RETURNING jsonb), '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb 'null', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a' ERROR ON ERROR);
+ERROR:  SQL/JSON member not found
+SELECT JSON_EXISTS(jsonb 'null', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'strict $.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'lax $.a');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{}', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"b": 1, "a": 2}', '$.a');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a.b');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": {"b": 1}}', '$.a.b');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.a.b');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING 1 AS x);
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING '1' AS x);
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 2 AS y);
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 1 AS y);
+ json_exists 
+-------------
+ f
+(1 row)
+
+-- extension: boolean expressions
+SELECT JSON_EXISTS(jsonb '1', '$ > 2');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a > 2' ERROR ON ERROR);
+ json_exists 
+-------------
+ t
+(1 row)
+
+-- JSON_VALUE
+SELECT JSON_VALUE(NULL::jsonb, '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$' RETURNING int);
+ json_value 
+------------
+           
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'true', '$');
+ json_value 
+------------
+ true
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'true', '$' RETURNING bool);
+ json_value 
+------------
+ t
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$');
+ json_value 
+------------
+ 123
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING int) + 234;
+ ?column? 
+----------
+      357
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING text);
+ json_value 
+------------
+ 123
+(1 row)
+
+/* jsonb bytea ??? */
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING bytea);
+ json_value 
+------------
+ \x313233
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1.23', '$');
+ json_value 
+------------
+ 1.23
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1.23', '$' RETURNING int);
+ json_value 
+------------
+          1
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING numeric);
+ json_value 
+------------
+       1.23
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for integer: "1.23"
+SELECT JSON_VALUE(jsonb '"aaa"', '$');
+ json_value 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING text);
+ json_value 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(5));
+ json_value 
+------------
+ aaa  
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(2));
+ json_value 
+------------
+ aa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json ERROR ON ERROR);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb ERROR ON ERROR);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING json);
+ json_value 
+------------
+ "\"aaa\""
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING jsonb);
+ json_value 
+------------
+ "\"aaa\""
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int);
+ json_value 
+------------
+           
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for integer: "aaa"
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int DEFAULT 111 ON ERROR);
+ json_value 
+------------
+        111
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"123"', '$' RETURNING int) + 234;
+ ?column? 
+----------
+      357
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"2017-02-20"', '$' RETURNING date) + 9;
+  ?column?  
+------------
+ 03-01-2017
+(1 row)
+
+-- Test NULL checks execution in domain types
+CREATE DOMAIN sqljsonb_int_not_null AS int NOT NULL;
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null NULL ON ERROR);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null DEFAULT NULL ON ERROR);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '[]', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[]', '$' ERROR ON ERROR);
+ERROR:  SQL/JSON scalar required
+SELECT JSON_VALUE(jsonb '{}', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '{}', '$' ERROR ON ERROR);
+ERROR:  SQL/JSON scalar required
+SELECT JSON_VALUE(jsonb '1', '$.a');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' ERROR ON ERROR);
+ERROR:  SQL/JSON member not found
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 'error' ON ERROR);
+ json_value 
+------------
+ error
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY ERROR ON ERROR);
+ERROR:  no SQL/JSON item
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 2 ON ERROR);
+ json_value 
+------------
+ 2
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT 2 ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' NULL ON EMPTY DEFAULT '2' ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON EMPTY DEFAULT '3' ON ERROR);
+ json_value 
+------------
+ 2
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY DEFAULT '3' ON ERROR);
+ json_value 
+------------
+ 3
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+ERROR:  more than one SQL/JSON item
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' DEFAULT '0' ON ERROR);
+ json_value 
+------------
+ 0
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for integer: " "
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+ json_value 
+------------
+          5
+(1 row)
+
+SELECT JSON_VALUE(jsonb '["1"]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+ json_value 
+------------
+          1
+(1 row)
+
+SELECT
+	x,
+	JSON_VALUE(
+		jsonb '{"a": 1, "b": 2}',
+		'$.* ? (@ > $x)' PASSING x AS x
+		RETURNING int
+		DEFAULT -1 ON EMPTY
+		DEFAULT -2 ON ERROR
+	) y
+FROM
+	generate_series(0, 2) x;
+ x | y  
+---+----
+ 0 | -2
+ 1 |  2
+ 2 | -1
+(3 rows)
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a);
+ json_value 
+------------
+ (1,2)
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a RETURNING point);
+ json_value 
+------------
+ (1,2)
+(1 row)
+
+-- Test timestamptz passing and output
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+          json_value          
+------------------------------
+ Tue Feb 20 18:34:56 2018 PST
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamptz);
+          json_value          
+------------------------------
+ Tue Feb 20 18:34:56 2018 PST
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamp);
+        json_value        
+--------------------------
+ Tue Feb 20 18:34:56 2018
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+         json_value          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+         json_value          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+-- JSON_QUERY
+SELECT
+	JSON_QUERY(js, '$'),
+	JSON_QUERY(js, '$' WITHOUT WRAPPER),
+	JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
+	JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
+	JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
+FROM
+	(VALUES
+		(jsonb 'null'),
+		('12.3'),
+		('true'),
+		('"aaa"'),
+		('[1, null, "2"]'),
+		('{"a": 1, "b": [2]}')
+	) foo(js);
+     json_query     |     json_query     |     json_query     |      json_query      |      json_query      
+--------------------+--------------------+--------------------+----------------------+----------------------
+ null               | null               | [null]             | [null]               | [null]
+ 12.3               | 12.3               | [12.3]             | [12.3]               | [12.3]
+ true               | true               | [true]             | [true]               | [true]
+ "aaa"              | "aaa"              | ["aaa"]            | ["aaa"]              | ["aaa"]
+ [1, null, "2"]     | [1, null, "2"]     | [1, null, "2"]     | [[1, null, "2"]]     | [[1, null, "2"]]
+ {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
+(6 rows)
+
+SELECT
+	JSON_QUERY(js, 'strict $[*]') AS "unspec",
+	JSON_QUERY(js, 'strict $[*]' WITHOUT WRAPPER) AS "without",
+	JSON_QUERY(js, 'strict $[*]' WITH CONDITIONAL WRAPPER) AS "with cond",
+	JSON_QUERY(js, 'strict $[*]' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
+	JSON_QUERY(js, 'strict $[*]' WITH ARRAY WRAPPER) AS "with"
+FROM
+	(VALUES
+		(jsonb '1'),
+		('[]'),
+		('[null]'),
+		('[12.3]'),
+		('[true]'),
+		('["aaa"]'),
+		('[[1, 2, 3]]'),
+		('[{"a": 1, "b": [2]}]'),
+		('[1, "2", null, [3]]')
+	) foo(js);
+       unspec       |      without       |      with cond      |     with uncond      |         with         
+--------------------+--------------------+---------------------+----------------------+----------------------
+                    |                    |                     |                      | 
+                    |                    |                     |                      | 
+ null               | null               | [null]              | [null]               | [null]
+ 12.3               | 12.3               | [12.3]              | [12.3]               | [12.3]
+ true               | true               | [true]              | [true]               | [true]
+ "aaa"              | "aaa"              | ["aaa"]             | ["aaa"]              | ["aaa"]
+ [1, 2, 3]          | [1, 2, 3]          | [1, 2, 3]           | [[1, 2, 3]]          | [[1, 2, 3]]
+ {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]}  | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
+                    |                    | [1, "2", null, [3]] | [1, "2", null, [3]]  | [1, "2", null, [3]]
+(9 rows)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES ON SCALAR STRING);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES);
+ json_query 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES ON SCALAR STRING);
+ json_query 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' OMIT QUOTES ERROR ON ERROR);
+ERROR:  invalid input syntax for type json
+DETAIL:  Token "aaa" is invalid.
+CONTEXT:  JSON data, line 1: aaa
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING json OMIT QUOTES ERROR ON ERROR);
+ERROR:  invalid input syntax for type json
+DETAIL:  Token "aaa" is invalid.
+CONTEXT:  JSON data, line 1: aaa
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING bytea FORMAT JSON OMIT QUOTES ERROR ON ERROR);
+ json_query 
+------------
+ \x616161
+(1 row)
+
+-- QUOTES behavior should not be specified when WITH WRAPPER used:
+-- Should fail
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES)...
+                                                        ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES)...
+                                                        ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: ...N_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTE...
+                                                             ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: ...N_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTE...
+                                                             ^
+-- Should succeed
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER OMIT QUOTES);
+ json_query 
+------------
+ [1]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER KEEP QUOTES);
+ json_query 
+------------
+ [1]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]');
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' NULL ON EMPTY);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ARRAY ON EMPTY);
+ json_query 
+------------
+ []
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY OBJECT ON EMPTY);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY NULL ON ERROR);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY ARRAY ON ERROR);
+ json_query 
+------------
+ []
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY ERROR ON ERROR);
+ERROR:  no SQL/JSON item
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON ERROR);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+ERROR:  more than one SQL/JSON item
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(10));
+ json_query 
+------------
+ [1, 2]    
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(3));
+ json_query 
+------------
+ [1,
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea);
+   json_query   
+----------------
+ \x5b312c20325d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea FORMAT JSON);
+   json_query   
+----------------
+ \x5b312c20325d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea FORMAT JSON EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING json EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING jsonb EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT
+	x, y,
+	JSON_QUERY(
+		jsonb '[1,2,3,4,5,null]',
+		'$[*] ? (@ >= $x && @ <= $y)'
+		PASSING x AS x, y AS y
+		WITH CONDITIONAL WRAPPER
+		EMPTY ARRAY ON EMPTY
+	) list
+FROM
+	generate_series(0, 4) x,
+	generate_series(0, 4) y;
+ x | y |     list     
+---+---+--------------
+ 0 | 0 | []
+ 0 | 1 | [1]
+ 0 | 2 | [1, 2]
+ 0 | 3 | [1, 2, 3]
+ 0 | 4 | [1, 2, 3, 4]
+ 1 | 0 | []
+ 1 | 1 | [1]
+ 1 | 2 | [1, 2]
+ 1 | 3 | [1, 2, 3]
+ 1 | 4 | [1, 2, 3, 4]
+ 2 | 0 | []
+ 2 | 1 | []
+ 2 | 2 | [2]
+ 2 | 3 | [2, 3]
+ 2 | 4 | [2, 3, 4]
+ 3 | 0 | []
+ 3 | 1 | []
+ 3 | 2 | []
+ 3 | 3 | [3]
+ 3 | 4 | [3, 4]
+ 4 | 0 | []
+ 4 | 1 | []
+ 4 | 2 | []
+ 4 | 3 | []
+ 4 | 4 | [4]
+(25 rows)
+
+-- Extension: record types returning
+CREATE TYPE sqljsonb_rec AS (a int, t text, js json, jb jsonb, jsa json[]);
+CREATE TYPE sqljsonb_reca AS (reca sqljsonb_rec[]);
+SELECT JSON_QUERY(jsonb '[{"a": 1, "b": "foo", "t": "aaa", "js": [1, "2", {}], "jb": {"x": [1, "2", {}]}},  {"a": 2}]', '$[0]' RETURNING sqljsonb_rec);
+                     json_query                      
+-----------------------------------------------------
+ (1,aaa,"[1, ""2"", {}]","{""x"": [1, ""2"", {}]}",)
+(1 row)
+
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"jsa":  [{"a": 1, "b": ["foo"]}, {"a": 2, "c": {}}, 123]}', '$' RETURNING sqljsonb_rec)).jsa);
+         unnest         
+------------------------
+ {"a": 1, "b": ["foo"]}
+ {"a": 2, "c": {}}
+ 123
+(3 rows)
+
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"reca": [{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]}', '$' RETURNING sqljsonb_reca)).reca);
+ a |      t      | js |     jb     | jsa 
+---+-------------+----+------------+-----
+ 1 | ["foo", []] |    |            | 
+ 2 |             |    | [{}, true] | 
+(2 rows)
+
+-- Extension: array types returning
+SELECT JSON_QUERY(jsonb '[1,2,null,"3"]', '$[*]' RETURNING int[] WITH WRAPPER);
+  json_query  
+--------------
+ {1,2,NULL,3}
+(1 row)
+
+SELECT * FROM unnest(JSON_QUERY(jsonb '[{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]', '$' RETURNING sqljsonb_rec[]));
+ a |      t      | js |     jb     | jsa 
+---+-------------+----+------------+-----
+ 1 | ["foo", []] |    |            | 
+ 2 |             |    | [{}, true] | 
+(2 rows)
+
+-- Extension: domain types returning
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.a' RETURNING sqljsonb_int_not_null);
+ json_query 
+------------
+          1
+(1 row)
+
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING sqljsonb_int_not_null);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+-- Test timestamptz passing and output
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+-- Test constraints
+CREATE TABLE test_jsonb_constraints (
+	js text,
+	i int,
+	x jsonb DEFAULT JSON_QUERY(jsonb '[1,2]', '$[*]' WITH WRAPPER)
+	CONSTRAINT test_jsonb_constraint1
+		CHECK (js IS JSON)
+	CONSTRAINT test_jsonb_constraint2
+		CHECK (JSON_EXISTS(js::jsonb, '$.a' PASSING i + 5 AS int, i::text AS txt, array[1,2,3] as arr))
+	CONSTRAINT test_jsonb_constraint3
+		CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT ('12' || i)::int ON EMPTY ERROR ON ERROR) > i)
+	CONSTRAINT test_jsonb_constraint4
+		CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
+	CONSTRAINT test_jsonb_constraint5
+		CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) >  'a')
+);
+\d test_jsonb_constraints
+                                                        Table "public.test_jsonb_constraints"
+ Column |  Type   | Collation | Nullable |                                                  Default                                                   
+--------+---------+-----------+----------+------------------------------------------------------------------------------------------------------------
+ js     | text    |           |          | 
+ i      | integer |           |          | 
+ x      | jsonb   |           |          | JSON_QUERY('[1, 2]'::jsonb, '$[*]' RETURNING jsonb WITH UNCONDITIONAL WRAPPER NULL ON EMPTY NULL ON ERROR)
+Check constraints:
+    "test_jsonb_constraint1" CHECK (js IS JSON)
+    "test_jsonb_constraint2" CHECK (JSON_EXISTS(js::jsonb, '$."a"' PASSING i + 5 AS int, i::text AS txt, ARRAY[1, 2, 3] AS arr FALSE ON ERROR))
+    "test_jsonb_constraint3" CHECK (JSON_VALUE(js::jsonb, '$."a"' RETURNING integer DEFAULT ('12'::text || i)::integer ON EMPTY ERROR ON ERROR) > i)
+    "test_jsonb_constraint4" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER NULL ON EMPTY EMPTY OBJECT ON ERROR) < '[10]'::jsonb)
+    "test_jsonb_constraint5" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING character(5) OMIT QUOTES EMPTY ARRAY ON EMPTY NULL ON ERROR) > 'a'::bpchar)
+
+SELECT check_clause
+FROM information_schema.check_constraints
+WHERE constraint_name LIKE 'test_jsonb_constraint%';
+                                                           check_clause                                                            
+-----------------------------------------------------------------------------------------------------------------------------------
+ ((js IS JSON))
+ (JSON_EXISTS((js)::jsonb, '$."a"' PASSING (i + 5) AS int, (i)::text AS txt, ARRAY[1, 2, 3] AS arr FALSE ON ERROR))
+ ((JSON_VALUE((js)::jsonb, '$."a"' RETURNING integer DEFAULT (('12'::text || i))::integer ON EMPTY ERROR ON ERROR) > i))
+ ((JSON_QUERY((js)::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER NULL ON EMPTY EMPTY OBJECT ON ERROR) < '[10]'::jsonb))
+ ((JSON_QUERY((js)::jsonb, '$."a"' RETURNING character(5) OMIT QUOTES EMPTY ARRAY ON EMPTY NULL ON ERROR) > 'a'::bpchar))
+(5 rows)
+
+SELECT adsrc FROM pg_attrdef WHERE adrelid = 'test_jsonb_constraints'::regclass;
+                                                   adsrc                                                    
+------------------------------------------------------------------------------------------------------------
+ JSON_QUERY('[1, 2]'::jsonb, '$[*]' RETURNING jsonb WITH UNCONDITIONAL WRAPPER NULL ON EMPTY NULL ON ERROR)
+(1 row)
+
+INSERT INTO test_jsonb_constraints VALUES ('', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint1"
+DETAIL:  Failing row contains (, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('1', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains (1, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('[]');
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains ([], null, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"b": 1}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains ({"b": 1}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint3"
+DETAIL:  Failing row contains ({"a": 1}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint5"
+DETAIL:  Failing row contains ({"a": 7}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint4"
+DETAIL:  Failing row contains ({"a": 10}, 1, [1, 2]).
+DROP TABLE test_jsonb_constraints;
+-- Extension: non-constant JSON path
+SELECT JSON_EXISTS(jsonb '{"a": 123}', '$' || '.' || 'a');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_VALUE(jsonb '{"a": 123}', '$' || '.' || 'a');
+ json_value 
+------------
+ 123
+(1 row)
+
+SELECT JSON_VALUE(jsonb '{"a": 123}', '$' || '.' || 'b' DEFAULT 'foo' ON EMPTY);
+ json_value 
+------------
+ foo
+(1 row)
+
+SELECT JSON_QUERY(jsonb '{"a": 123}', '$' || '.' || 'a');
+ json_query 
+------------
+ 123
+(1 row)
+
+SELECT JSON_QUERY(jsonb '{"a": 123}', '$' || '.' || 'a' WITH WRAPPER);
+ json_query 
+------------
+ [123]
+(1 row)
+
+-- Should fail (invalid path)
+SELECT JSON_QUERY(jsonb '{"a": 123}', 'error' || ' ' || 'error');
+ERROR:  bad jsonpath representation
+DETAIL:  syntax error, unexpected IDENT_P at or near " "
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index fb806a8..0c2f241 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -206,11 +206,12 @@ WHERE p1.oid != p2.oid AND
 ORDER BY 1, 2;
  proargtypes | proargtypes 
 -------------+-------------
+          25 |         114
           25 |        1042
           25 |        1043
         1114 |        1184
         1560 |        1562
-(4 rows)
+(5 rows)
 
 SELECT DISTINCT p1.proargtypes[1], p2.proargtypes[1]
 FROM pg_proc AS p1, pg_proc AS p2
diff --git a/src/test/regress/expected/sqljson.out b/src/test/regress/expected/sqljson.out
new file mode 100644
index 0000000..be2add5
--- /dev/null
+++ b/src/test/regress/expected/sqljson.out
@@ -0,0 +1,940 @@
+-- JSON_OBJECT()
+SELECT JSON_OBJECT();
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING json);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING json FORMAT JSON);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING jsonb);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING jsonb FORMAT JSON);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING text);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON);
+ json_object 
+-------------
+ {}
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING UTF8);
+ERROR:  cannot set JSON encoding for non-bytea output types
+LINE 1: SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING UTF8)...
+                                          ^
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
+ERROR:  unrecognized JSON encoding: invalid_encoding
+SELECT JSON_OBJECT(RETURNING bytea);
+ json_object 
+-------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON);
+ json_object 
+-------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF8);
+ json_object 
+-------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF16);
+ERROR:  unsupported JSON encoding
+LINE 1: SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF1...
+                                           ^
+HINT:  only UTF8 JSON encoding is supported
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF32);
+ERROR:  unsupported JSON encoding
+LINE 1: SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF3...
+                                           ^
+HINT:  only UTF8 JSON encoding is supported
+SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON);
+ERROR:  cannot use non-string types with explicit FORMAT JSON clause
+LINE 1: SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON);
+                                            ^
+SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON ENCODING UTF8);
+ERROR:  JSON ENCODING clause is only allowed for bytea input type
+LINE 1: SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON ENCODING UTF...
+                                            ^
+SELECT JSON_OBJECT('foo': NULL::json FORMAT JSON);
+WARNING:  FORMAT JSON has no effect for json and jsonb types
+  json_object   
+----------------
+ {"foo" : null}
+(1 row)
+
+SELECT JSON_OBJECT('foo': NULL::json FORMAT JSON ENCODING UTF8);
+ERROR:  JSON ENCODING clause is only allowed for bytea input type
+LINE 1: SELECT JSON_OBJECT('foo': NULL::json FORMAT JSON ENCODING UT...
+                                             ^
+SELECT JSON_OBJECT('foo': NULL::jsonb FORMAT JSON);
+WARNING:  FORMAT JSON has no effect for json and jsonb types
+  json_object   
+----------------
+ {"foo" : null}
+(1 row)
+
+SELECT JSON_OBJECT('foo': NULL::jsonb FORMAT JSON ENCODING UTF8);
+ERROR:  JSON ENCODING clause is only allowed for bytea input type
+LINE 1: SELECT JSON_OBJECT('foo': NULL::jsonb FORMAT JSON ENCODING U...
+                                              ^
+SELECT JSON_OBJECT(NULL: 1);
+ERROR:  argument 3 cannot be null
+HINT:  Object keys should be text.
+SELECT JSON_OBJECT('a': 2 + 3);
+ json_object 
+-------------
+ {"a" : 5}
+(1 row)
+
+SELECT JSON_OBJECT('a' VALUE 2 + 3);
+ json_object 
+-------------
+ {"a" : 5}
+(1 row)
+
+--SELECT JSON_OBJECT(KEY 'a' VALUE 2 + 3);
+SELECT JSON_OBJECT('a' || 2: 1);
+ json_object 
+-------------
+ {"a2" : 1}
+(1 row)
+
+SELECT JSON_OBJECT(('a' || 2) VALUE 1);
+ json_object 
+-------------
+ {"a2" : 1}
+(1 row)
+
+--SELECT JSON_OBJECT('a' || 2 VALUE 1);
+--SELECT JSON_OBJECT(KEY 'a' || 2 VALUE 1);
+SELECT JSON_OBJECT('a': 2::text);
+ json_object 
+-------------
+ {"a" : "2"}
+(1 row)
+
+SELECT JSON_OBJECT('a' VALUE 2::text);
+ json_object 
+-------------
+ {"a" : "2"}
+(1 row)
+
+--SELECT JSON_OBJECT(KEY 'a' VALUE 2::text);
+SELECT JSON_OBJECT(1::text: 2);
+ json_object 
+-------------
+ {"1" : 2}
+(1 row)
+
+SELECT JSON_OBJECT((1::text) VALUE 2);
+ json_object 
+-------------
+ {"1" : 2}
+(1 row)
+
+--SELECT JSON_OBJECT(1::text VALUE 2);
+--SELECT JSON_OBJECT(KEY 1::text VALUE 2);
+SELECT JSON_OBJECT(json '[1]': 123);
+ERROR:  key value must be scalar, not array, composite, or json
+SELECT JSON_OBJECT(ARRAY[1,2,3]: 'aaa');
+ERROR:  key value must be scalar, not array, composite, or json
+SELECT JSON_OBJECT(
+	'a': '123',
+	1.23: 123,
+	'c': json '[ 1,true,{ } ]',
+	'd': jsonb '{ "x" : 123.45 }'
+);
+                              json_object                               
+------------------------------------------------------------------------
+ {"a" : "123", "1.23" : 123, "c" : [ 1,true,{ } ], "d" : {"x": 123.45}}
+(1 row)
+
+SELECT JSON_OBJECT(
+	'a': '123',
+	1.23: 123,
+	'c': json '[ 1,true,{ } ]',
+	'd': jsonb '{ "x" : 123.45 }'
+	RETURNING jsonb
+);
+                            json_object                            
+-------------------------------------------------------------------
+ {"a": "123", "c": [1, true, {}], "d": {"x": 123.45}, "1.23": 123}
+(1 row)
+
+/*
+SELECT JSON_OBJECT(
+	'a': '123',
+	KEY 1.23 VALUE 123,
+	'c' VALUE json '[1, true, {}]'
+);
+*/
+SELECT JSON_OBJECT('a': '123', 'b': JSON_OBJECT('a': 111, 'b': 'aaa'));
+                  json_object                  
+-----------------------------------------------
+ {"a" : "123", "b" : {"a" : 111, "b" : "aaa"}}
+(1 row)
+
+SELECT JSON_OBJECT('a': '123', 'b': JSON_OBJECT('a': 111, 'b': 'aaa' RETURNING jsonb));
+                 json_object                 
+---------------------------------------------
+ {"a" : "123", "b" : {"a": 111, "b": "aaa"}}
+(1 row)
+
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING text));
+      json_object      
+-----------------------
+ {"a" : "{\"b\" : 1}"}
+(1 row)
+
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING text) FORMAT JSON);
+    json_object    
+-------------------
+ {"a" : {"b" : 1}}
+(1 row)
+
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING bytea));
+           json_object           
+---------------------------------
+ {"a" : "\\x7b226222203a20317d"}
+(1 row)
+
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING bytea) FORMAT JSON);
+    json_object    
+-------------------
+ {"a" : {"b" : 1}}
+(1 row)
+
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2);
+           json_object            
+----------------------------------
+ {"a" : "1", "b" : null, "c" : 2}
+(1 row)
+
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2 NULL ON NULL);
+           json_object            
+----------------------------------
+ {"a" : "1", "b" : null, "c" : 2}
+(1 row)
+
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2 ABSENT ON NULL);
+     json_object      
+----------------------
+ {"a" : "1", "c" : 2}
+(1 row)
+
+SELECT JSON_OBJECT(1: 1, '1': NULL WITH UNIQUE);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '1': NULL ABSENT ON NULL WITH UNIQUE);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '1': NULL NULL ON NULL WITH UNIQUE RETURNING jsonb);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '1': NULL ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 NULL ON NULL WITH UNIQUE);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITH UNIQUE);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITHOUT UNIQUE);
+    json_object     
+--------------------
+ {"1" : 1, "1" : 1}
+(1 row)
+
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITHOUT UNIQUE RETURNING jsonb);
+ json_object 
+-------------
+ {"1": 1}
+(1 row)
+
+SELECT JSON_OBJECT(1: 1, '2': NULL, '3': 1, 4: NULL, '5': 'a' ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+        json_object         
+----------------------------
+ {"1": 1, "3": 1, "5": "a"}
+(1 row)
+
+-- JSON_ARRAY()
+SELECT JSON_ARRAY();
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING json);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING json FORMAT JSON);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING jsonb);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING jsonb FORMAT JSON);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING text);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON);
+ json_array 
+------------
+ []
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING UTF8);
+ERROR:  cannot set JSON encoding for non-bytea output types
+LINE 1: SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING UTF8);
+                                         ^
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
+ERROR:  unrecognized JSON encoding: invalid_encoding
+SELECT JSON_ARRAY(RETURNING bytea);
+ json_array 
+------------
+ \x5b5d
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON);
+ json_array 
+------------
+ \x5b5d
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF8);
+ json_array 
+------------
+ \x5b5d
+(1 row)
+
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF16);
+ERROR:  unsupported JSON encoding
+LINE 1: SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF16...
+                                          ^
+HINT:  only UTF8 JSON encoding is supported
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF32);
+ERROR:  unsupported JSON encoding
+LINE 1: SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF32...
+                                          ^
+HINT:  only UTF8 JSON encoding is supported
+SELECT JSON_ARRAY('aaa', 111, true, array[1,2,3], NULL, json '{"a": [1]}', jsonb '["a",3]');
+                    json_array                     
+---------------------------------------------------
+ ["aaa", 111, true, [1,2,3], {"a": [1]}, ["a", 3]]
+(1 row)
+
+SELECT JSON_ARRAY('a',  NULL, 'b' NULL   ON NULL);
+    json_array    
+------------------
+ ["a", null, "b"]
+(1 row)
+
+SELECT JSON_ARRAY('a',  NULL, 'b' ABSENT ON NULL);
+ json_array 
+------------
+ ["a", "b"]
+(1 row)
+
+SELECT JSON_ARRAY(NULL, NULL, 'b' ABSENT ON NULL);
+ json_array 
+------------
+ ["b"]
+(1 row)
+
+SELECT JSON_ARRAY('a',  NULL, 'b' NULL   ON NULL RETURNING jsonb);
+    json_array    
+------------------
+ ["a", null, "b"]
+(1 row)
+
+SELECT JSON_ARRAY('a',  NULL, 'b' ABSENT ON NULL RETURNING jsonb);
+ json_array 
+------------
+ ["a", "b"]
+(1 row)
+
+SELECT JSON_ARRAY(NULL, NULL, 'b' ABSENT ON NULL RETURNING jsonb);
+ json_array 
+------------
+ ["b"]
+(1 row)
+
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' RETURNING text));
+          json_array           
+-------------------------------
+ ["[\"{ \\\"a\\\" : 123 }\"]"]
+(1 row)
+
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' FORMAT JSON RETURNING text));
+      json_array       
+-----------------------
+ ["[{ \"a\" : 123 }]"]
+(1 row)
+
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' FORMAT JSON RETURNING text) FORMAT JSON);
+    json_array     
+-------------------
+ [[{ "a" : 123 }]]
+(1 row)
+
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i));
+ json_array 
+------------
+ [1, 2, 4]
+(1 row)
+
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i));
+ json_array 
+------------
+ [[1,2],   +
+  [3,4]]
+(1 row)
+
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) RETURNING jsonb);
+    json_array    
+------------------
+ [[1, 2], [3, 4]]
+(1 row)
+
+--SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) NULL ON NULL);
+--SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) NULL ON NULL RETURNING jsonb);
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (3), (1), (NULL), (2)) foo(i) ORDER BY i);
+ json_array 
+------------
+ [1, 2, 3]
+(1 row)
+
+-- Should fail
+SELECT JSON_ARRAY(SELECT FROM (VALUES (1)) foo(i));
+ERROR:  subquery must return only one column
+LINE 1: SELECT JSON_ARRAY(SELECT FROM (VALUES (1)) foo(i));
+               ^
+SELECT JSON_ARRAY(SELECT i, i FROM (VALUES (1)) foo(i));
+ERROR:  subquery must return only one column
+LINE 1: SELECT JSON_ARRAY(SELECT i, i FROM (VALUES (1)) foo(i));
+               ^
+SELECT JSON_ARRAY(SELECT * FROM (VALUES (1, 2)) foo(i, j));
+ERROR:  subquery must return only one column
+LINE 1: SELECT JSON_ARRAY(SELECT * FROM (VALUES (1, 2)) foo(i, j));
+               ^
+-- JSON_ARRAYAGG()
+SELECT	JSON_ARRAYAGG(i) IS NULL,
+		JSON_ARRAYAGG(i RETURNING jsonb) IS NULL
+FROM generate_series(1, 0) i;
+ ?column? | ?column? 
+----------+----------
+ t        | t
+(1 row)
+
+SELECT	JSON_ARRAYAGG(i),
+		JSON_ARRAYAGG(i RETURNING jsonb)
+FROM generate_series(1, 5) i;
+  json_arrayagg  |  json_arrayagg  
+-----------------+-----------------
+ [1, 2, 3, 4, 5] | [1, 2, 3, 4, 5]
+(1 row)
+
+SELECT JSON_ARRAYAGG(i ORDER BY i DESC)
+FROM generate_series(1, 5) i;
+  json_arrayagg  
+-----------------
+ [5, 4, 3, 2, 1]
+(1 row)
+
+SELECT JSON_ARRAYAGG(i::text::json)
+FROM generate_series(1, 5) i;
+  json_arrayagg  
+-----------------
+ [1, 2, 3, 4, 5]
+(1 row)
+
+SELECT JSON_ARRAYAGG(JSON_ARRAY(i, i + 1 RETURNING text) FORMAT JSON)
+FROM generate_series(1, 5) i;
+              json_arrayagg               
+------------------------------------------
+ [[1, 2], [2, 3], [3, 4], [4, 5], [5, 6]]
+(1 row)
+
+SELECT	JSON_ARRAYAGG(NULL),
+		JSON_ARRAYAGG(NULL RETURNING jsonb)
+FROM generate_series(1, 5);
+ json_arrayagg | json_arrayagg 
+---------------+---------------
+ []            | []
+(1 row)
+
+SELECT	JSON_ARRAYAGG(NULL NULL ON NULL),
+		JSON_ARRAYAGG(NULL NULL ON NULL RETURNING jsonb)
+FROM generate_series(1, 5);
+         json_arrayagg          |         json_arrayagg          
+--------------------------------+--------------------------------
+ [null, null, null, null, null] | [null, null, null, null, null]
+(1 row)
+
+SELECT
+	JSON_ARRAYAGG(bar),
+	JSON_ARRAYAGG(bar RETURNING jsonb),
+	JSON_ARRAYAGG(bar ABSENT ON NULL),
+	JSON_ARRAYAGG(bar ABSENT ON NULL RETURNING jsonb),
+	JSON_ARRAYAGG(bar NULL ON NULL),
+	JSON_ARRAYAGG(bar NULL ON NULL RETURNING jsonb),
+	JSON_ARRAYAGG(foo),
+	JSON_ARRAYAGG(foo RETURNING jsonb),
+	JSON_ARRAYAGG(foo ORDER BY bar) FILTER (WHERE bar > 2),
+	JSON_ARRAYAGG(foo ORDER BY bar RETURNING jsonb) FILTER (WHERE bar > 2)
+FROM
+	(VALUES (NULL), (3), (1), (NULL), (NULL), (5), (2), (4), (NULL)) foo(bar);
+  json_arrayagg  |  json_arrayagg  |  json_arrayagg  |  json_arrayagg  |              json_arrayagg              |              json_arrayagg              |  json_arrayagg  |                                                      json_arrayagg                                                       | json_arrayagg |            json_arrayagg             
+-----------------+-----------------+-----------------+-----------------+-----------------------------------------+-----------------------------------------+-----------------+--------------------------------------------------------------------------------------------------------------------------+---------------+--------------------------------------
+ [3, 1, 5, 2, 4] | [3, 1, 5, 2, 4] | [3, 1, 5, 2, 4] | [3, 1, 5, 2, 4] | [null, 3, 1, null, null, 5, 2, 4, null] | [null, 3, 1, null, null, 5, 2, 4, null] | [{"bar":null}, +| [{"bar": null}, {"bar": 3}, {"bar": 1}, {"bar": null}, {"bar": null}, {"bar": 5}, {"bar": 2}, {"bar": 4}, {"bar": null}] | [{"bar":3},  +| [{"bar": 3}, {"bar": 4}, {"bar": 5}]
+                 |                 |                 |                 |                                         |                                         |  {"bar":3},    +|                                                                                                                          |  {"bar":4},  +| 
+                 |                 |                 |                 |                                         |                                         |  {"bar":1},    +|                                                                                                                          |  {"bar":5}]   | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":null}, +|                                                                                                                          |               | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":null}, +|                                                                                                                          |               | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":5},    +|                                                                                                                          |               | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":2},    +|                                                                                                                          |               | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":4},    +|                                                                                                                          |               | 
+                 |                 |                 |                 |                                         |                                         |  {"bar":null}]  |                                                                                                                          |               | 
+(1 row)
+
+SELECT
+	bar, JSON_ARRAYAGG(bar) FILTER (WHERE bar > 2) OVER (PARTITION BY foo.bar % 2)
+FROM
+	(VALUES (NULL), (3), (1), (NULL), (NULL), (5), (2), (4), (NULL), (5), (4)) foo(bar);
+ bar | json_arrayagg 
+-----+---------------
+   4 | [4, 4]
+   4 | [4, 4]
+   2 | [4, 4]
+   5 | [5, 3, 5]
+   3 | [5, 3, 5]
+   1 | [5, 3, 5]
+   5 | [5, 3, 5]
+     | 
+     | 
+     | 
+     | 
+(11 rows)
+
+-- JSON_OBJECTAGG()
+SELECT	JSON_OBJECTAGG('key': 1) IS NULL,
+		JSON_OBJECTAGG('key': 1 RETURNING jsonb) IS NULL
+WHERE FALSE;
+ ?column? | ?column? 
+----------+----------
+ t        | t
+(1 row)
+
+SELECT JSON_OBJECTAGG(NULL: 1);
+ERROR:  field name must not be null
+SELECT JSON_OBJECTAGG(NULL: 1 RETURNING jsonb);
+ERROR:  field name must not be null
+SELECT
+	JSON_OBJECTAGG(i: i),
+--	JSON_OBJECTAGG(i VALUE i),
+--	JSON_OBJECTAGG(KEY i VALUE i),
+	JSON_OBJECTAGG(i: i RETURNING jsonb)
+FROM
+	generate_series(1, 5) i;
+                 json_objectagg                  |              json_objectagg              
+-------------------------------------------------+------------------------------------------
+ { "1" : 1, "2" : 2, "3" : 3, "4" : 4, "5" : 5 } | {"1": 1, "2": 2, "3": 3, "4": 4, "5": 5}
+(1 row)
+
+SELECT
+	JSON_OBJECTAGG(k: v),
+	JSON_OBJECTAGG(k: v NULL ON NULL),
+	JSON_OBJECTAGG(k: v ABSENT ON NULL),
+	JSON_OBJECTAGG(k: v RETURNING jsonb),
+	JSON_OBJECTAGG(k: v NULL ON NULL RETURNING jsonb),
+	JSON_OBJECTAGG(k: v ABSENT ON NULL RETURNING jsonb)
+FROM
+	(VALUES (1, 1), (1, NULL), (2, NULL), (3, 3)) foo(k, v);
+                json_objectagg                |                json_objectagg                |    json_objectagg    |         json_objectagg         |         json_objectagg         |  json_objectagg  
+----------------------------------------------+----------------------------------------------+----------------------+--------------------------------+--------------------------------+------------------
+ { "1" : 1, "1" : null, "2" : null, "3" : 3 } | { "1" : 1, "1" : null, "2" : null, "3" : 3 } | { "1" : 1, "3" : 3 } | {"1": null, "2": null, "3": 3} | {"1": null, "2": null, "3": 3} | {"1": 1, "3": 3}
+(1 row)
+
+SELECT JSON_OBJECTAGG(k: v WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (0, NULL), (3, NULL), (2, 2), (4, NULL)) foo(k, v);
+    json_objectagg    
+----------------------
+ { "1" : 1, "2" : 2 }
+(1 row)
+
+SELECT JSON_OBJECTAGG(k: v WITH UNIQUE KEYS RETURNING jsonb)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+ERROR:  duplicate JSON key "1"
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS RETURNING jsonb)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+ERROR:  duplicate JSON key "1"
+-- Test JSON_OBJECT deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
+                                        QUERY PLAN                                        
+------------------------------------------------------------------------------------------
+ Result
+   Output: JSON_OBJECT('foo' : '1'::json FORMAT JSON, 'bar' : 'baz'::text RETURNING json)
+(2 rows)
+
+CREATE VIEW json_object_view AS
+SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
+\sv json_object_view
+CREATE OR REPLACE VIEW public.json_object_view AS
+ SELECT JSON_OBJECT('foo' : '1'::text FORMAT JSON, 'bar' : 'baz'::text RETURNING json) AS "json_object"
+DROP VIEW json_object_view;
+-- Test JSON_ARRAY deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
+                          QUERY PLAN                           
+---------------------------------------------------------------
+ Result
+   Output: JSON_ARRAY('1'::json FORMAT JSON, 2 RETURNING json)
+(2 rows)
+
+CREATE VIEW json_array_view AS
+SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
+\sv json_array_view
+CREATE OR REPLACE VIEW public.json_array_view AS
+ SELECT JSON_ARRAY('1'::text FORMAT JSON, 2 RETURNING json) AS "json_array"
+DROP VIEW json_array_view;
+-- Test JSON_OBJECTAGG deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+                                                              QUERY PLAN                                                              
+--------------------------------------------------------------------------------------------------------------------------------------
+ Aggregate
+   Output: JSON_OBJECTAGG(i : (('111'::text || (i)::text))::bytea FORMAT JSON WITH UNIQUE KEYS RETURNING text) FILTER (WHERE (i > 3))
+   ->  Function Scan on pg_catalog.generate_series i
+         Output: i
+         Function Call: generate_series(1, 5)
+(5 rows)
+
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) OVER (PARTITION BY i % 2)
+FROM generate_series(1,5) i;
+                                                            QUERY PLAN                                                             
+-----------------------------------------------------------------------------------------------------------------------------------
+ WindowAgg
+   Output: JSON_OBJECTAGG(i : (('111'::text || (i)::text))::bytea FORMAT JSON WITH UNIQUE KEYS RETURNING text) OVER (?), ((i % 2))
+   ->  Sort
+         Output: ((i % 2)), i
+         Sort Key: ((i.i % 2))
+         ->  Function Scan on pg_catalog.generate_series i
+               Output: (i % 2), i
+               Function Call: generate_series(1, 5)
+(8 rows)
+
+CREATE VIEW json_objectagg_view AS
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+\sv json_objectagg_view
+CREATE OR REPLACE VIEW public.json_objectagg_view AS
+ SELECT JSON_OBJECTAGG(i.i : (('111'::text || i.i)::bytea) FORMAT JSON WITH UNIQUE KEYS RETURNING text) FILTER (WHERE i.i > 3) AS "json_objectagg"
+   FROM generate_series(1, 5) i(i)
+DROP VIEW json_objectagg_view;
+-- Test JSON_ARRAYAGG deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+                                                         QUERY PLAN                                                          
+-----------------------------------------------------------------------------------------------------------------------------
+ Aggregate
+   Output: JSON_ARRAYAGG((('111'::text || (i)::text))::bytea FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE (i > 3))
+   ->  Function Scan on pg_catalog.generate_series i
+         Output: i
+         Function Call: generate_series(1, 5)
+(5 rows)
+
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) OVER (PARTITION BY i % 2)
+FROM generate_series(1,5) i;
+                                                        QUERY PLAN                                                        
+--------------------------------------------------------------------------------------------------------------------------
+ WindowAgg
+   Output: JSON_ARRAYAGG((('111'::text || (i)::text))::bytea FORMAT JSON NULL ON NULL RETURNING text) OVER (?), ((i % 2))
+   ->  Sort
+         Output: ((i % 2)), i
+         Sort Key: ((i.i % 2))
+         ->  Function Scan on pg_catalog.generate_series i
+               Output: (i % 2), i
+               Function Call: generate_series(1, 5)
+(8 rows)
+
+CREATE VIEW json_arrayagg_view AS
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+\sv json_arrayagg_view
+CREATE OR REPLACE VIEW public.json_arrayagg_view AS
+ SELECT JSON_ARRAYAGG((('111'::text || i.i)::bytea) FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE i.i > 3) AS "json_arrayagg"
+   FROM generate_series(1, 5) i(i)
+DROP VIEW json_arrayagg_view;
+-- Test JSON_ARRAY(subquery) deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i) RETURNING jsonb);
+                             QUERY PLAN                              
+---------------------------------------------------------------------
+ Result
+   Output: $0
+   InitPlan 1 (returns $0)
+     ->  Aggregate
+           Output: JSON_ARRAYAGG("*VALUES*".column1 RETURNING jsonb)
+           ->  Values Scan on "*VALUES*"
+                 Output: "*VALUES*".column1
+(7 rows)
+
+CREATE VIEW json_array_subquery_view AS
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i) RETURNING jsonb);
+\sv json_array_subquery_view
+CREATE OR REPLACE VIEW public.json_array_subquery_view AS
+ SELECT ( SELECT JSON_ARRAYAGG(q.a RETURNING jsonb) AS "json_arrayagg"
+           FROM ( SELECT foo.i
+                   FROM ( VALUES (1), (2), (NULL::integer), (4)) foo(i)) q(a)) AS "json_array"
+DROP VIEW json_array_subquery_view;
+-- IS JSON predicate
+SELECT NULL IS JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL IS NOT JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL::json IS JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL::jsonb IS JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL::text IS JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL::bytea IS JSON;
+ ?column? 
+----------
+ 
+(1 row)
+
+SELECT NULL::int IS JSON;
+ERROR:  cannot use type integer in IS JSON predicate
+SELECT '' IS JSON;
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT bytea '\x00' IS JSON;
+ERROR:  invalid byte sequence for encoding "UTF8": 0x00
+CREATE TABLE test_is_json (js text);
+INSERT INTO test_is_json VALUES
+ (NULL),
+ (''),
+ ('123'),
+ ('"aaa "'),
+ ('true'),
+ ('null'),
+ ('[]'),
+ ('[1, "2", {}]'),
+ ('{}'),
+ ('{ "a": 1, "b": null }'),
+ ('{ "a": 1, "a": null }'),
+ ('{ "a": 1, "b": [{ "a": 1 }, { "a": 2 }] }'),
+ ('{ "a": 1, "b": [{ "a": 1, "b": 0, "a": 2 }] }'),
+ ('aaa'),
+ ('{a:1}'),
+ ('["a",]');
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	test_is_json;
+                      js                       | IS JSON | IS NOT JSON | IS VALUE | IS OBJECT | IS ARRAY | IS SCALAR | WITHOUT UNIQUE | WITH UNIQUE 
+-----------------------------------------------+---------+-------------+----------+-----------+----------+-----------+----------------+-------------
+                                               |         |             |          |           |          |           |                | 
+                                               | f       | t           | f        | f         | f        | f         | f              | f
+ 123                                           | t       | f           | t        | f         | f        | t         | t              | t
+ "aaa "                                        | t       | f           | t        | f         | f        | t         | t              | t
+ true                                          | t       | f           | t        | f         | f        | t         | t              | t
+ null                                          | t       | f           | t        | f         | f        | t         | t              | t
+ []                                            | t       | f           | t        | f         | t        | f         | t              | t
+ [1, "2", {}]                                  | t       | f           | t        | f         | t        | f         | t              | t
+ {}                                            | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": null }                         | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "a": null }                         | t       | f           | t        | t         | f        | f         | t              | f
+ { "a": 1, "b": [{ "a": 1 }, { "a": 2 }] }     | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": [{ "a": 1, "b": 0, "a": 2 }] } | t       | f           | t        | t         | f        | f         | t              | f
+ aaa                                           | f       | t           | f        | f         | f        | f         | f              | f
+ {a:1}                                         | f       | t           | f        | f         | f        | f         | f              | f
+ ["a",]                                        | f       | t           | f        | f         | f        | f         | f              | f
+(16 rows)
+
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js::json FROM test_is_json WHERE js IS JSON) foo(js);
+                      js                       | IS JSON | IS NOT JSON | IS VALUE | IS OBJECT | IS ARRAY | IS SCALAR | WITHOUT UNIQUE | WITH UNIQUE 
+-----------------------------------------------+---------+-------------+----------+-----------+----------+-----------+----------------+-------------
+ 123                                           | t       | f           | t        | f         | f        | t         | t              | t
+ "aaa "                                        | t       | f           | t        | f         | f        | t         | t              | t
+ true                                          | t       | f           | t        | f         | f        | t         | t              | t
+ null                                          | t       | f           | t        | f         | f        | t         | t              | t
+ []                                            | t       | f           | t        | f         | t        | f         | t              | t
+ [1, "2", {}]                                  | t       | f           | t        | f         | t        | f         | t              | t
+ {}                                            | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": null }                         | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "a": null }                         | t       | f           | t        | t         | f        | f         | t              | f
+ { "a": 1, "b": [{ "a": 1 }, { "a": 2 }] }     | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": [{ "a": 1, "b": 0, "a": 2 }] } | t       | f           | t        | t         | f        | f         | t              | f
+(11 rows)
+
+SELECT
+	js0,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js, js::bytea FROM test_is_json WHERE js IS JSON) foo(js0, js);
+                      js0                      | IS JSON | IS NOT JSON | IS VALUE | IS OBJECT | IS ARRAY | IS SCALAR | WITHOUT UNIQUE | WITH UNIQUE 
+-----------------------------------------------+---------+-------------+----------+-----------+----------+-----------+----------------+-------------
+ 123                                           | t       | f           | t        | f         | f        | t         | t              | t
+ "aaa "                                        | t       | f           | t        | f         | f        | t         | t              | t
+ true                                          | t       | f           | t        | f         | f        | t         | t              | t
+ null                                          | t       | f           | t        | f         | f        | t         | t              | t
+ []                                            | t       | f           | t        | f         | t        | f         | t              | t
+ [1, "2", {}]                                  | t       | f           | t        | f         | t        | f         | t              | t
+ {}                                            | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": null }                         | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "a": null }                         | t       | f           | t        | t         | f        | f         | t              | f
+ { "a": 1, "b": [{ "a": 1 }, { "a": 2 }] }     | t       | f           | t        | t         | f        | f         | t              | t
+ { "a": 1, "b": [{ "a": 1, "b": 0, "a": 2 }] } | t       | f           | t        | t         | f        | f         | t              | f
+(11 rows)
+
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js::jsonb FROM test_is_json WHERE js IS JSON) foo(js);
+                 js                  | IS JSON | IS NOT JSON | IS VALUE | IS OBJECT | IS ARRAY | IS SCALAR | WITHOUT UNIQUE | WITH UNIQUE 
+-------------------------------------+---------+-------------+----------+-----------+----------+-----------+----------------+-------------
+ 123                                 | t       | f           | t        | f         | f        | t         | t              | t
+ "aaa "                              | t       | f           | t        | f         | f        | t         | t              | t
+ true                                | t       | f           | t        | f         | f        | t         | t              | t
+ null                                | t       | f           | t        | f         | f        | t         | t              | t
+ []                                  | t       | f           | t        | f         | t        | f         | t              | t
+ [1, "2", {}]                        | t       | f           | t        | f         | t        | f         | t              | t
+ {}                                  | t       | f           | t        | t         | f        | f         | t              | t
+ {"a": 1, "b": null}                 | t       | f           | t        | t         | f        | f         | t              | t
+ {"a": null}                         | t       | f           | t        | t         | f        | f         | t              | t
+ {"a": 1, "b": [{"a": 1}, {"a": 2}]} | t       | f           | t        | t         | f        | f         | t              | t
+ {"a": 1, "b": [{"a": 2, "b": 0}]}   | t       | f           | t        | t         | f        | f         | t              | t
+(11 rows)
+
+-- Test IS JSON deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT '1' IS JSON AS "any", ('1' || i) IS JSON SCALAR AS "scalar", '[]' IS NOT JSON ARRAY AS "array", '{}' IS JSON OBJECT WITH UNIQUE AS "object" FROM generate_series(1, 3) i;
+                                                                        QUERY PLAN                                                                        
+----------------------------------------------------------------------------------------------------------------------------------------------------------
+ Function Scan on pg_catalog.generate_series i
+   Output: ('1'::text IS JSON), (('1'::text || (i)::text) IS JSON SCALAR), (NOT ('[]'::text IS JSON ARRAY)), ('{}'::text IS JSON OBJECT WITH UNIQUE KEYS)
+   Function Call: generate_series(1, 3)
+(3 rows)
+
+CREATE VIEW is_json_view AS
+SELECT '1' IS JSON AS "any", ('1' || i) IS JSON SCALAR AS "scalar", '[]' IS NOT JSON ARRAY AS "array", '{}' IS JSON OBJECT WITH UNIQUE AS "object" FROM generate_series(1, 3) i;
+\sv is_json_view
+CREATE OR REPLACE VIEW public.is_json_view AS
+ SELECT '1'::text IS JSON AS "any",
+    '1'::text || i.i IS JSON SCALAR AS scalar,
+    NOT '[]'::text IS JSON ARRAY AS "array",
+    '{}'::text IS JSON OBJECT WITH UNIQUE KEYS AS object
+   FROM generate_series(1, 3) i(i)
+DROP VIEW is_json_view;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index ccec68e..7065d54 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -109,7 +109,7 @@ test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combo
 # ----------
 # Another group of parallel tests (JSON related)
 # ----------
-test: json jsonb json_encoding jsonpath json_jsonpath jsonb_jsonpath
+test: json jsonb json_encoding jsonpath json_jsonpath jsonb_jsonpath jsonb_sqljson sqljson
 
 # ----------
 # Another group of parallel tests
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index f22a682..bf341e7 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -161,6 +161,9 @@ test: json_encoding
 test: jsonpath
 test: json_jsonpath
 test: jsonb_jsonpath
+test: sqljson
+test: json_sqljson
+test: jsonb_sqljson
 test: indirect_toast
 test: equivclass
 test: plancache
diff --git a/src/test/regress/sql/json_sqljson.sql b/src/test/regress/sql/json_sqljson.sql
new file mode 100644
index 0000000..4f30fa4
--- /dev/null
+++ b/src/test/regress/sql/json_sqljson.sql
@@ -0,0 +1,11 @@
+-- JSON_EXISTS
+
+SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+
+-- JSON_VALUE
+
+SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+
+-- JSON_QUERY
+
+SELECT JSON_QUERY(NULL FORMAT JSON, '$');
diff --git a/src/test/regress/sql/jsonb_sqljson.sql b/src/test/regress/sql/jsonb_sqljson.sql
new file mode 100644
index 0000000..a801bcf
--- /dev/null
+++ b/src/test/regress/sql/jsonb_sqljson.sql
@@ -0,0 +1,287 @@
+-- JSON_EXISTS
+
+SELECT JSON_EXISTS(NULL::jsonb, '$');
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+SELECT JSON_EXISTS(JSON_OBJECT(RETURNING jsonb), '$');
+
+SELECT JSON_EXISTS(jsonb '1', '$');
+SELECT JSON_EXISTS(jsonb 'null', '$');
+SELECT JSON_EXISTS(jsonb '[]', '$');
+
+SELECT JSON_EXISTS(jsonb '1', '$.a');
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a');
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a' ERROR ON ERROR);
+SELECT JSON_EXISTS(jsonb 'null', '$.a');
+SELECT JSON_EXISTS(jsonb '[]', '$.a');
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'strict $.a');
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'lax $.a');
+SELECT JSON_EXISTS(jsonb '{}', '$.a');
+SELECT JSON_EXISTS(jsonb '{"b": 1, "a": 2}', '$.a');
+
+SELECT JSON_EXISTS(jsonb '1', '$.a.b');
+SELECT JSON_EXISTS(jsonb '{"a": {"b": 1}}', '$.a.b');
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.a.b');
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING 1 AS x);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING '1' AS x);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 2 AS y);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 1 AS y);
+
+-- extension: boolean expressions
+SELECT JSON_EXISTS(jsonb '1', '$ > 2');
+SELECT JSON_EXISTS(jsonb '1', '$.a > 2' ERROR ON ERROR);
+
+-- JSON_VALUE
+
+SELECT JSON_VALUE(NULL::jsonb, '$');
+
+SELECT JSON_VALUE(jsonb 'null', '$');
+SELECT JSON_VALUE(jsonb 'null', '$' RETURNING int);
+
+SELECT JSON_VALUE(jsonb 'true', '$');
+SELECT JSON_VALUE(jsonb 'true', '$' RETURNING bool);
+
+SELECT JSON_VALUE(jsonb '123', '$');
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING int) + 234;
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING text);
+/* jsonb bytea ??? */
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING bytea);
+
+SELECT JSON_VALUE(jsonb '1.23', '$');
+SELECT JSON_VALUE(jsonb '1.23', '$' RETURNING int);
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING numeric);
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING int ERROR ON ERROR);
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$');
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING text);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(5));
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(2));
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING json);
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING jsonb);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int DEFAULT 111 ON ERROR);
+SELECT JSON_VALUE(jsonb '"123"', '$' RETURNING int) + 234;
+
+SELECT JSON_VALUE(jsonb '"2017-02-20"', '$' RETURNING date) + 9;
+
+-- Test NULL checks execution in domain types
+CREATE DOMAIN sqljsonb_int_not_null AS int NOT NULL;
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null);
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null NULL ON ERROR);
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null DEFAULT NULL ON ERROR);
+
+SELECT JSON_VALUE(jsonb '[]', '$');
+SELECT JSON_VALUE(jsonb '[]', '$' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '{}', '$');
+SELECT JSON_VALUE(jsonb '{}', '$' ERROR ON ERROR);
+
+SELECT JSON_VALUE(jsonb '1', '$.a');
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 'error' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 2 ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT 2 ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' NULL ON EMPTY DEFAULT '2' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON EMPTY DEFAULT '3' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY DEFAULT '3' ON ERROR);
+
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' DEFAULT '0' ON ERROR);
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+SELECT JSON_VALUE(jsonb '["1"]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+
+SELECT
+	x,
+	JSON_VALUE(
+		jsonb '{"a": 1, "b": 2}',
+		'$.* ? (@ > $x)' PASSING x AS x
+		RETURNING int
+		DEFAULT -1 ON EMPTY
+		DEFAULT -2 ON ERROR
+	) y
+FROM
+	generate_series(0, 2) x;
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a);
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a RETURNING point);
+
+-- Test timestamptz passing and output
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamptz);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamp);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+
+-- JSON_QUERY
+
+SELECT
+	JSON_QUERY(js, '$'),
+	JSON_QUERY(js, '$' WITHOUT WRAPPER),
+	JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
+	JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
+	JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
+FROM
+	(VALUES
+		(jsonb 'null'),
+		('12.3'),
+		('true'),
+		('"aaa"'),
+		('[1, null, "2"]'),
+		('{"a": 1, "b": [2]}')
+	) foo(js);
+
+SELECT
+	JSON_QUERY(js, 'strict $[*]') AS "unspec",
+	JSON_QUERY(js, 'strict $[*]' WITHOUT WRAPPER) AS "without",
+	JSON_QUERY(js, 'strict $[*]' WITH CONDITIONAL WRAPPER) AS "with cond",
+	JSON_QUERY(js, 'strict $[*]' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
+	JSON_QUERY(js, 'strict $[*]' WITH ARRAY WRAPPER) AS "with"
+FROM
+	(VALUES
+		(jsonb '1'),
+		('[]'),
+		('[null]'),
+		('[12.3]'),
+		('[true]'),
+		('["aaa"]'),
+		('[[1, 2, 3]]'),
+		('[{"a": 1, "b": [2]}]'),
+		('[1, "2", null, [3]]')
+	) foo(js);
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES ON SCALAR STRING);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES ON SCALAR STRING);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' OMIT QUOTES ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING json OMIT QUOTES ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING bytea FORMAT JSON OMIT QUOTES ERROR ON ERROR);
+
+-- QUOTES behavior should not be specified when WITH WRAPPER used:
+-- Should fail
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTES);
+-- Should succeed
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER KEEP QUOTES);
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]');
+SELECT JSON_QUERY(jsonb '[]', '$[*]' NULL ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ARRAY ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY OBJECT ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY);
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY NULL ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY ARRAY ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON ERROR);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(10));
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(3));
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea FORMAT JSON);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea FORMAT JSON EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING json EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING jsonb EMPTY OBJECT ON ERROR);
+
+SELECT
+	x, y,
+	JSON_QUERY(
+		jsonb '[1,2,3,4,5,null]',
+		'$[*] ? (@ >= $x && @ <= $y)'
+		PASSING x AS x, y AS y
+		WITH CONDITIONAL WRAPPER
+		EMPTY ARRAY ON EMPTY
+	) list
+FROM
+	generate_series(0, 4) x,
+	generate_series(0, 4) y;
+
+-- Extension: record types returning
+CREATE TYPE sqljsonb_rec AS (a int, t text, js json, jb jsonb, jsa json[]);
+CREATE TYPE sqljsonb_reca AS (reca sqljsonb_rec[]);
+
+SELECT JSON_QUERY(jsonb '[{"a": 1, "b": "foo", "t": "aaa", "js": [1, "2", {}], "jb": {"x": [1, "2", {}]}},  {"a": 2}]', '$[0]' RETURNING sqljsonb_rec);
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"jsa":  [{"a": 1, "b": ["foo"]}, {"a": 2, "c": {}}, 123]}', '$' RETURNING sqljsonb_rec)).jsa);
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"reca": [{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]}', '$' RETURNING sqljsonb_reca)).reca);
+
+-- Extension: array types returning
+SELECT JSON_QUERY(jsonb '[1,2,null,"3"]', '$[*]' RETURNING int[] WITH WRAPPER);
+SELECT * FROM unnest(JSON_QUERY(jsonb '[{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]', '$' RETURNING sqljsonb_rec[]));
+
+-- Extension: domain types returning
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.a' RETURNING sqljsonb_int_not_null);
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING sqljsonb_int_not_null);
+
+-- Test timestamptz passing and output
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+
+-- Test constraints
+
+CREATE TABLE test_jsonb_constraints (
+	js text,
+	i int,
+	x jsonb DEFAULT JSON_QUERY(jsonb '[1,2]', '$[*]' WITH WRAPPER)
+	CONSTRAINT test_jsonb_constraint1
+		CHECK (js IS JSON)
+	CONSTRAINT test_jsonb_constraint2
+		CHECK (JSON_EXISTS(js::jsonb, '$.a' PASSING i + 5 AS int, i::text AS txt, array[1,2,3] as arr))
+	CONSTRAINT test_jsonb_constraint3
+		CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT ('12' || i)::int ON EMPTY ERROR ON ERROR) > i)
+	CONSTRAINT test_jsonb_constraint4
+		CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
+	CONSTRAINT test_jsonb_constraint5
+		CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) >  'a')
+);
+
+\d test_jsonb_constraints
+
+SELECT check_clause
+FROM information_schema.check_constraints
+WHERE constraint_name LIKE 'test_jsonb_constraint%';
+
+SELECT adsrc FROM pg_attrdef WHERE adrelid = 'test_jsonb_constraints'::regclass;
+
+INSERT INTO test_jsonb_constraints VALUES ('', 1);
+INSERT INTO test_jsonb_constraints VALUES ('1', 1);
+INSERT INTO test_jsonb_constraints VALUES ('[]');
+INSERT INTO test_jsonb_constraints VALUES ('{"b": 1}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
+
+DROP TABLE test_jsonb_constraints;
+
+-- Extension: non-constant JSON path
+SELECT JSON_EXISTS(jsonb '{"a": 123}', '$' || '.' || 'a');
+SELECT JSON_VALUE(jsonb '{"a": 123}', '$' || '.' || 'a');
+SELECT JSON_VALUE(jsonb '{"a": 123}', '$' || '.' || 'b' DEFAULT 'foo' ON EMPTY);
+SELECT JSON_QUERY(jsonb '{"a": 123}', '$' || '.' || 'a');
+SELECT JSON_QUERY(jsonb '{"a": 123}', '$' || '.' || 'a' WITH WRAPPER);
+-- Should fail (invalid path)
+SELECT JSON_QUERY(jsonb '{"a": 123}', 'error' || ' ' || 'error');
diff --git a/src/test/regress/sql/sqljson.sql b/src/test/regress/sql/sqljson.sql
new file mode 100644
index 0000000..4f3c06d
--- /dev/null
+++ b/src/test/regress/sql/sqljson.sql
@@ -0,0 +1,378 @@
+-- JSON_OBJECT()
+SELECT JSON_OBJECT();
+SELECT JSON_OBJECT(RETURNING json);
+SELECT JSON_OBJECT(RETURNING json FORMAT JSON);
+SELECT JSON_OBJECT(RETURNING jsonb);
+SELECT JSON_OBJECT(RETURNING jsonb FORMAT JSON);
+SELECT JSON_OBJECT(RETURNING text);
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON);
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING UTF8);
+SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
+SELECT JSON_OBJECT(RETURNING bytea);
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON);
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF8);
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF16);
+SELECT JSON_OBJECT(RETURNING bytea FORMAT JSON ENCODING UTF32);
+
+SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON);
+SELECT JSON_OBJECT('foo': NULL::int FORMAT JSON ENCODING UTF8);
+SELECT JSON_OBJECT('foo': NULL::json FORMAT JSON);
+SELECT JSON_OBJECT('foo': NULL::json FORMAT JSON ENCODING UTF8);
+SELECT JSON_OBJECT('foo': NULL::jsonb FORMAT JSON);
+SELECT JSON_OBJECT('foo': NULL::jsonb FORMAT JSON ENCODING UTF8);
+
+SELECT JSON_OBJECT(NULL: 1);
+SELECT JSON_OBJECT('a': 2 + 3);
+SELECT JSON_OBJECT('a' VALUE 2 + 3);
+--SELECT JSON_OBJECT(KEY 'a' VALUE 2 + 3);
+SELECT JSON_OBJECT('a' || 2: 1);
+SELECT JSON_OBJECT(('a' || 2) VALUE 1);
+--SELECT JSON_OBJECT('a' || 2 VALUE 1);
+--SELECT JSON_OBJECT(KEY 'a' || 2 VALUE 1);
+SELECT JSON_OBJECT('a': 2::text);
+SELECT JSON_OBJECT('a' VALUE 2::text);
+--SELECT JSON_OBJECT(KEY 'a' VALUE 2::text);
+SELECT JSON_OBJECT(1::text: 2);
+SELECT JSON_OBJECT((1::text) VALUE 2);
+--SELECT JSON_OBJECT(1::text VALUE 2);
+--SELECT JSON_OBJECT(KEY 1::text VALUE 2);
+SELECT JSON_OBJECT(json '[1]': 123);
+SELECT JSON_OBJECT(ARRAY[1,2,3]: 'aaa');
+
+SELECT JSON_OBJECT(
+	'a': '123',
+	1.23: 123,
+	'c': json '[ 1,true,{ } ]',
+	'd': jsonb '{ "x" : 123.45 }'
+);
+
+SELECT JSON_OBJECT(
+	'a': '123',
+	1.23: 123,
+	'c': json '[ 1,true,{ } ]',
+	'd': jsonb '{ "x" : 123.45 }'
+	RETURNING jsonb
+);
+
+/*
+SELECT JSON_OBJECT(
+	'a': '123',
+	KEY 1.23 VALUE 123,
+	'c' VALUE json '[1, true, {}]'
+);
+*/
+
+SELECT JSON_OBJECT('a': '123', 'b': JSON_OBJECT('a': 111, 'b': 'aaa'));
+SELECT JSON_OBJECT('a': '123', 'b': JSON_OBJECT('a': 111, 'b': 'aaa' RETURNING jsonb));
+
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING text));
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING text) FORMAT JSON);
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING bytea));
+SELECT JSON_OBJECT('a': JSON_OBJECT('b': 1 RETURNING bytea) FORMAT JSON);
+
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2);
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2 NULL ON NULL);
+SELECT JSON_OBJECT('a': '1', 'b': NULL, 'c': 2 ABSENT ON NULL);
+
+SELECT JSON_OBJECT(1: 1, '1': NULL WITH UNIQUE);
+SELECT JSON_OBJECT(1: 1, '1': NULL ABSENT ON NULL WITH UNIQUE);
+SELECT JSON_OBJECT(1: 1, '1': NULL NULL ON NULL WITH UNIQUE RETURNING jsonb);
+SELECT JSON_OBJECT(1: 1, '1': NULL ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 NULL ON NULL WITH UNIQUE);
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITH UNIQUE);
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITHOUT UNIQUE);
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+SELECT JSON_OBJECT(1: 1, '2': NULL, '1': 1 ABSENT ON NULL WITHOUT UNIQUE RETURNING jsonb);
+SELECT JSON_OBJECT(1: 1, '2': NULL, '3': 1, 4: NULL, '5': 'a' ABSENT ON NULL WITH UNIQUE RETURNING jsonb);
+
+
+-- JSON_ARRAY()
+SELECT JSON_ARRAY();
+SELECT JSON_ARRAY(RETURNING json);
+SELECT JSON_ARRAY(RETURNING json FORMAT JSON);
+SELECT JSON_ARRAY(RETURNING jsonb);
+SELECT JSON_ARRAY(RETURNING jsonb FORMAT JSON);
+SELECT JSON_ARRAY(RETURNING text);
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON);
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING UTF8);
+SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
+SELECT JSON_ARRAY(RETURNING bytea);
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON);
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF8);
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF16);
+SELECT JSON_ARRAY(RETURNING bytea FORMAT JSON ENCODING UTF32);
+
+SELECT JSON_ARRAY('aaa', 111, true, array[1,2,3], NULL, json '{"a": [1]}', jsonb '["a",3]');
+
+SELECT JSON_ARRAY('a',  NULL, 'b' NULL   ON NULL);
+SELECT JSON_ARRAY('a',  NULL, 'b' ABSENT ON NULL);
+SELECT JSON_ARRAY(NULL, NULL, 'b' ABSENT ON NULL);
+SELECT JSON_ARRAY('a',  NULL, 'b' NULL   ON NULL RETURNING jsonb);
+SELECT JSON_ARRAY('a',  NULL, 'b' ABSENT ON NULL RETURNING jsonb);
+SELECT JSON_ARRAY(NULL, NULL, 'b' ABSENT ON NULL RETURNING jsonb);
+
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' RETURNING text));
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' FORMAT JSON RETURNING text));
+SELECT JSON_ARRAY(JSON_ARRAY('{ "a" : 123 }' FORMAT JSON RETURNING text) FORMAT JSON);
+
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i));
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i));
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) RETURNING jsonb);
+--SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) NULL ON NULL);
+--SELECT JSON_ARRAY(SELECT i FROM (VALUES (NULL::int[]), ('{1,2}'), (NULL), (NULL), ('{3,4}'), (NULL)) foo(i) NULL ON NULL RETURNING jsonb);
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (3), (1), (NULL), (2)) foo(i) ORDER BY i);
+-- Should fail
+SELECT JSON_ARRAY(SELECT FROM (VALUES (1)) foo(i));
+SELECT JSON_ARRAY(SELECT i, i FROM (VALUES (1)) foo(i));
+SELECT JSON_ARRAY(SELECT * FROM (VALUES (1, 2)) foo(i, j));
+
+-- JSON_ARRAYAGG()
+SELECT	JSON_ARRAYAGG(i) IS NULL,
+		JSON_ARRAYAGG(i RETURNING jsonb) IS NULL
+FROM generate_series(1, 0) i;
+
+SELECT	JSON_ARRAYAGG(i),
+		JSON_ARRAYAGG(i RETURNING jsonb)
+FROM generate_series(1, 5) i;
+
+SELECT JSON_ARRAYAGG(i ORDER BY i DESC)
+FROM generate_series(1, 5) i;
+
+SELECT JSON_ARRAYAGG(i::text::json)
+FROM generate_series(1, 5) i;
+
+SELECT JSON_ARRAYAGG(JSON_ARRAY(i, i + 1 RETURNING text) FORMAT JSON)
+FROM generate_series(1, 5) i;
+
+SELECT	JSON_ARRAYAGG(NULL),
+		JSON_ARRAYAGG(NULL RETURNING jsonb)
+FROM generate_series(1, 5);
+
+SELECT	JSON_ARRAYAGG(NULL NULL ON NULL),
+		JSON_ARRAYAGG(NULL NULL ON NULL RETURNING jsonb)
+FROM generate_series(1, 5);
+
+SELECT
+	JSON_ARRAYAGG(bar),
+	JSON_ARRAYAGG(bar RETURNING jsonb),
+	JSON_ARRAYAGG(bar ABSENT ON NULL),
+	JSON_ARRAYAGG(bar ABSENT ON NULL RETURNING jsonb),
+	JSON_ARRAYAGG(bar NULL ON NULL),
+	JSON_ARRAYAGG(bar NULL ON NULL RETURNING jsonb),
+	JSON_ARRAYAGG(foo),
+	JSON_ARRAYAGG(foo RETURNING jsonb),
+	JSON_ARRAYAGG(foo ORDER BY bar) FILTER (WHERE bar > 2),
+	JSON_ARRAYAGG(foo ORDER BY bar RETURNING jsonb) FILTER (WHERE bar > 2)
+FROM
+	(VALUES (NULL), (3), (1), (NULL), (NULL), (5), (2), (4), (NULL)) foo(bar);
+
+SELECT
+	bar, JSON_ARRAYAGG(bar) FILTER (WHERE bar > 2) OVER (PARTITION BY foo.bar % 2)
+FROM
+	(VALUES (NULL), (3), (1), (NULL), (NULL), (5), (2), (4), (NULL), (5), (4)) foo(bar);
+
+-- JSON_OBJECTAGG()
+SELECT	JSON_OBJECTAGG('key': 1) IS NULL,
+		JSON_OBJECTAGG('key': 1 RETURNING jsonb) IS NULL
+WHERE FALSE;
+
+SELECT JSON_OBJECTAGG(NULL: 1);
+
+SELECT JSON_OBJECTAGG(NULL: 1 RETURNING jsonb);
+
+SELECT
+	JSON_OBJECTAGG(i: i),
+--	JSON_OBJECTAGG(i VALUE i),
+--	JSON_OBJECTAGG(KEY i VALUE i),
+	JSON_OBJECTAGG(i: i RETURNING jsonb)
+FROM
+	generate_series(1, 5) i;
+
+SELECT
+	JSON_OBJECTAGG(k: v),
+	JSON_OBJECTAGG(k: v NULL ON NULL),
+	JSON_OBJECTAGG(k: v ABSENT ON NULL),
+	JSON_OBJECTAGG(k: v RETURNING jsonb),
+	JSON_OBJECTAGG(k: v NULL ON NULL RETURNING jsonb),
+	JSON_OBJECTAGG(k: v ABSENT ON NULL RETURNING jsonb)
+FROM
+	(VALUES (1, 1), (1, NULL), (2, NULL), (3, 3)) foo(k, v);
+
+SELECT JSON_OBJECTAGG(k: v WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS)
+FROM (VALUES (1, 1), (0, NULL), (3, NULL), (2, 2), (4, NULL)) foo(k, v);
+
+SELECT JSON_OBJECTAGG(k: v WITH UNIQUE KEYS RETURNING jsonb)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+
+SELECT JSON_OBJECTAGG(k: v ABSENT ON NULL WITH UNIQUE KEYS RETURNING jsonb)
+FROM (VALUES (1, 1), (1, NULL), (2, 2)) foo(k, v);
+
+-- Test JSON_OBJECT deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
+
+CREATE VIEW json_object_view AS
+SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
+
+\sv json_object_view
+
+DROP VIEW json_object_view;
+
+-- Test JSON_ARRAY deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
+
+CREATE VIEW json_array_view AS
+SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
+
+\sv json_array_view
+
+DROP VIEW json_array_view;
+
+-- Test JSON_OBJECTAGG deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) OVER (PARTITION BY i % 2)
+FROM generate_series(1,5) i;
+
+CREATE VIEW json_objectagg_view AS
+SELECT JSON_OBJECTAGG(i: ('111' || i)::bytea FORMAT JSON WITH UNIQUE RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+
+\sv json_objectagg_view
+
+DROP VIEW json_objectagg_view;
+
+-- Test JSON_ARRAYAGG deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) OVER (PARTITION BY i % 2)
+FROM generate_series(1,5) i;
+
+CREATE VIEW json_arrayagg_view AS
+SELECT JSON_ARRAYAGG(('111' || i)::bytea FORMAT JSON NULL ON NULL RETURNING text) FILTER (WHERE i > 3)
+FROM generate_series(1,5) i;
+
+\sv json_arrayagg_view
+
+DROP VIEW json_arrayagg_view;
+
+-- Test JSON_ARRAY(subquery) deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i) RETURNING jsonb);
+
+CREATE VIEW json_array_subquery_view AS
+SELECT JSON_ARRAY(SELECT i FROM (VALUES (1), (2), (NULL), (4)) foo(i) RETURNING jsonb);
+
+\sv json_array_subquery_view
+
+DROP VIEW json_array_subquery_view;
+
+-- IS JSON predicate
+SELECT NULL IS JSON;
+SELECT NULL IS NOT JSON;
+SELECT NULL::json IS JSON;
+SELECT NULL::jsonb IS JSON;
+SELECT NULL::text IS JSON;
+SELECT NULL::bytea IS JSON;
+SELECT NULL::int IS JSON;
+
+SELECT '' IS JSON;
+
+SELECT bytea '\x00' IS JSON;
+
+CREATE TABLE test_is_json (js text);
+
+INSERT INTO test_is_json VALUES
+ (NULL),
+ (''),
+ ('123'),
+ ('"aaa "'),
+ ('true'),
+ ('null'),
+ ('[]'),
+ ('[1, "2", {}]'),
+ ('{}'),
+ ('{ "a": 1, "b": null }'),
+ ('{ "a": 1, "a": null }'),
+ ('{ "a": 1, "b": [{ "a": 1 }, { "a": 2 }] }'),
+ ('{ "a": 1, "b": [{ "a": 1, "b": 0, "a": 2 }] }'),
+ ('aaa'),
+ ('{a:1}'),
+ ('["a",]');
+
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	test_is_json;
+
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js::json FROM test_is_json WHERE js IS JSON) foo(js);
+
+SELECT
+	js0,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js, js::bytea FROM test_is_json WHERE js IS JSON) foo(js0, js);
+
+SELECT
+	js,
+	js IS JSON "IS JSON",
+	js IS NOT JSON "IS NOT JSON",
+	js IS JSON VALUE "IS VALUE",
+	js IS JSON OBJECT "IS OBJECT",
+	js IS JSON ARRAY "IS ARRAY",
+	js IS JSON SCALAR "IS SCALAR",
+	js IS JSON WITHOUT UNIQUE KEYS "WITHOUT UNIQUE",
+	js IS JSON WITH UNIQUE KEYS "WITH UNIQUE"
+FROM
+	(SELECT js::jsonb FROM test_is_json WHERE js IS JSON) foo(js);
+
+-- Test IS JSON deparsing
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT '1' IS JSON AS "any", ('1' || i) IS JSON SCALAR AS "scalar", '[]' IS NOT JSON ARRAY AS "array", '{}' IS JSON OBJECT WITH UNIQUE AS "object" FROM generate_series(1, 3) i;
+
+CREATE VIEW is_json_view AS
+SELECT '1' IS JSON AS "any", ('1' || i) IS JSON SCALAR AS "scalar", '[]' IS NOT JSON ARRAY AS "array", '{}' IS JSON OBJECT WITH UNIQUE AS "object" FROM generate_series(1, 3) i;
+
+\sv is_json_view
+
+DROP VIEW is_json_view;
