From 66fc176ebf221e815cb56e91e77beae2e255f6aa Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Thu, 6 Jul 2023 10:44:20 +0200 Subject: [PATCH 7/9] Implementation of DEFAULT clause - default expressions for session variables When the evaluation of default expression fails, we remove related entry from sessionvars hash table. Then sessionvars can contain only sucessfully initialized values. Then we don't need special flag for badly initialized session variables. --- doc/src/sgml/catalogs.sgml | 8 ++ doc/src/sgml/ref/create_variable.sgml | 13 ++- src/backend/catalog/pg_variable.c | 27 ++++++ src/backend/commands/session_variable.c | 88 ++++++++++++++++++- src/backend/parser/gram.y | 15 +++- src/backend/parser/parse_agg.c | 2 + src/backend/parser/parse_expr.c | 4 + src/backend/parser/parse_func.c | 1 + src/bin/pg_dump/pg_dump.c | 14 +++ src/bin/pg_dump/pg_dump.h | 1 + src/bin/pg_dump/t/002_pg_dump.pl | 36 ++++++++ src/bin/psql/describe.c | 4 +- src/include/catalog/pg_variable.h | 3 + src/include/nodes/parsenodes.h | 1 + src/include/parser/parse_node.h | 1 + src/test/regress/expected/psql.out | 36 ++++---- .../regress/expected/session_variables.out | 73 +++++++++++++-- src/test/regress/sql/session_variables.sql | 48 ++++++++++ 18 files changed, 342 insertions(+), 33 deletions(-) diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index d5019e7871..61ad740854 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -9807,6 +9807,14 @@ SCRAM-SHA-256$<iteration count>:&l + + + vardefexpr pg_node_tree + + + The internal representation of the variable default value + + diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml index 001a30c85b..6d6e29ac4b 100644 --- a/doc/src/sgml/ref/create_variable.sgml +++ b/doc/src/sgml/ref/create_variable.sgml @@ -27,7 +27,7 @@ PostgreSQL documentation CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] name [ AS ] data_type ] [ COLLATE collation ] - [ { ON COMMIT DROP | ON TRANSACTION END RESET } ] + [ DEFAULT default_expr ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ] @@ -111,6 +111,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] + DEFAULT default_expr + + + The DEFAULT clause can be used to assign a default + value to a session variable. This expression is evaluated when the session + variable is first accessed for reading and had not yet been assigned a value. + + + + ON COMMIT DROP diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c index 89495d13ca..a0a599e343 100644 --- a/src/backend/catalog/pg_variable.c +++ b/src/backend/catalog/pg_variable.c @@ -24,6 +24,9 @@ #include "catalog/pg_variable.h" #include "commands/session_variable.h" #include "miscadmin.h" +#include "parser/parse_coerce.h" +#include "parser/parse_collate.h" +#include "parser/parse_expr.h" #include "parser/parse_type.h" #include "utils/builtins.h" #include "utils/lsyscache.h" @@ -37,6 +40,7 @@ static ObjectAddress create_variable(const char *varName, Oid varOwner, Oid varCollation, bool if_not_exists, + Node *varDefexpr, VariableEOXAction eoxaction); @@ -51,6 +55,7 @@ create_variable(const char *varName, Oid varOwner, Oid varCollation, bool if_not_exists, + Node *varDefexpr, VariableEOXAction eoxaction) { Acl *varacl; @@ -114,6 +119,11 @@ create_variable(const char *varName, values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation); values[Anum_pg_variable_vareoxaction - 1] = CharGetDatum(eoxaction); + if (varDefexpr) + values[Anum_pg_variable_vardefexpr - 1] = CStringGetTextDatum(nodeToString(varDefexpr)); + else + nulls[Anum_pg_variable_vardefexpr - 1] = true; + varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner, varNamespace); if (varacl != NULL) @@ -150,6 +160,11 @@ create_variable(const char *varName, record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL); free_object_addresses(addrs); + /* dependency on default expr */ + if (varDefexpr) + recordDependencyOnExpr(&myself, (Node *) varDefexpr, + NIL, DEPENDENCY_NORMAL); + /* dependency on owner */ recordDependencyOnOwner(VariableRelationId, varid, varOwner); @@ -185,6 +200,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) Oid collation; Oid typcollation; ObjectAddress variable; + Node *cooked_default = NULL; /* Check consistency of arguments */ if (stmt->eoxaction == VARIABLE_EOX_DROP @@ -226,6 +242,16 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) format_type_be(typid)), parser_errposition(pstate, stmt->collClause->location))); + if (stmt->defexpr) + { + cooked_default = transformExpr(pstate, stmt->defexpr, + EXPR_KIND_VARIABLE_DEFAULT); + + cooked_default = coerce_to_specific_type(pstate, + cooked_default, typid, "DEFAULT"); + assign_expr_collations(pstate, cooked_default); + } + variable = create_variable(stmt->variable->relname, namespaceid, typid, @@ -233,6 +259,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) varowner, collation, stmt->if_not_exists, + cooked_default, stmt->eoxaction); elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable", diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c index 436a3f63b7..6de7c20802 100644 --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -22,6 +22,7 @@ #include "executor/svariableReceiver.h" #include "funcapi.h" #include "miscadmin.h" +#include "optimizer/optimizer.h" #include "rewrite/rewriteHandler.h" #include "storage/lmgr.h" #include "storage/proc.h" @@ -538,11 +539,69 @@ invalidate_session_variable(SVariable svar) svar->is_valid = false; } +/* + * evaluate an expression + */ +static void +eval_assign_defexpr(SVariable svar, HeapTuple tup) +{ + Datum defexpr_value; + bool isnull; + + Assert(svar); + Assert(svar->is_valid); + Assert(HeapTupleIsValid(tup)); + + defexpr_value = SysCacheGetAttr(VARIABLEOID, + tup, + Anum_pg_variable_vardefexpr, + &isnull); + + if (!isnull) + { + EState *estate; + ExprState *defexprs; + Expr *defexpr; + char *defexpr_str; + Datum value; + MemoryContext oldcxt; + + estate = CreateExecutorState(); + + defexpr_str = TextDatumGetCString(defexpr_value); + defexpr = (Expr *) stringToNode(defexpr_str); + + oldcxt = MemoryContextSwitchTo(estate->es_query_cxt); + + defexpr = expression_planner((Expr *) defexpr); + defexprs = ExecInitExpr(defexpr, NULL); + + value = ExecEvalExprSwitchContext(defexprs, + GetPerTupleExprContext(estate), + &isnull); + + MemoryContextSwitchTo(oldcxt); + + if (!isnull) + { + oldcxt = MemoryContextSwitchTo(SVariableMemoryContext); + + svar->value = datumCopy(value, svar->typbyval, svar->typlen); + svar->freeval = svar->value != value; + svar->isnull = false; + + MemoryContextSwitchTo(oldcxt); + } + + FreeExecutorState(estate); + } +} + /* * Update attributes cached in svar */ static void -setup_session_variable(SVariable svar, Oid varid) +setup_session_variable(SVariable svar, Oid varid, bool is_write) { HeapTuple tup; Form_pg_variable varform; @@ -593,6 +652,9 @@ setup_session_variable(SVariable svar, Oid varid) svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID, ObjectIdGetDatum(varid)); + if (!is_write) + eval_assign_defexpr(svar, tup); + ReleaseSysCache(tup); } @@ -619,7 +681,7 @@ set_session_variable(SVariable svar, Datum value, bool isnull) */ if (!svar->is_valid) { - setup_session_variable(&locsvar, svar->varid); + setup_session_variable(&locsvar, svar->varid, false); _svar = &locsvar; } else @@ -746,7 +808,25 @@ get_session_variable(Oid varid) if (!svar->is_valid) { - setup_session_variable(svar, varid); + /* in this case we want to use defexp if it is defined */ + PG_TRY(); + { + /* + * In this case, the setup can execute default expression. When + * the execution of default expression fails, then we need to + * remove entry from session vars. + */ + setup_session_variable(svar, varid, false); + } + PG_CATCH(); + { + /* This entry cannot be valid, remove from sessionvars */ + hash_search(sessionvars, &varid, HASH_REMOVE, NULL); + + /* propagate the error */ + PG_RE_THROW(); + } + PG_END_TRY(); elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new entry in memory (emitted by READ)", get_namespace_name(get_session_variable_namespace(varid)), @@ -810,7 +890,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull) if (!found) { - setup_session_variable(svar, varid); + setup_session_variable(svar, varid, true); elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new entry in memory (emitted by WRITE)", get_namespace_name(get_session_variable_namespace(svar->varid)), diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index e9356b983c..d93036d19a 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -647,6 +647,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type PartitionBoundSpec %type hash_partbound %type hash_partbound_elem +%type OptSessionVarDefExpr %type json_format_clause_opt json_value_expr @@ -5061,30 +5062,36 @@ create_extension_opt_item: *****************************************************************************/ CreateSessionVarStmt: - CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OnEOXActionOption + CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr OnEOXActionOption { CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt); $4->relpersistence = $2; n->variable = $4; n->typeName = $6; n->collClause = (CollateClause *) $7; - n->eoxaction = $8; + n->defexpr = $8; + n->eoxaction = $9; n->if_not_exists = false; $$ = (Node *) n; } - | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OnEOXActionOption + | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr OnEOXActionOption { CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt); $7->relpersistence = $2; n->variable = $7; n->typeName = $9; n->collClause = (CollateClause *) $10; - n->eoxaction = $11; + n->defexpr = $11; + n->eoxaction = $12; n->if_not_exists = true; $$ = (Node *) n; } ; +OptSessionVarDefExpr: DEFAULT b_expr { $$ = $2; } + | /* EMPTY */ { $$ = NULL; } + ; + /* * Temporary session variables can be dropped on successful * transaction end like tables. diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index 30269708d6..6643ec3167 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -472,6 +472,7 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr) break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_VARIABLE_DEFAULT: if (isAgg) err = _("aggregate functions are not allowed in DEFAULT expressions"); @@ -920,6 +921,7 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_VARIABLE_DEFAULT: err = _("window functions are not allowed in DEFAULT expressions"); break; case EXPR_KIND_INDEX_EXPRESSION: diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 1382d2919b..d4a69ca474 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -547,6 +547,7 @@ expr_kind_allows_session_variables(ParseExprKind p_expr_kind) case EXPR_KIND_JOIN_USING: case EXPR_KIND_CYCLE_MARK: case EXPR_KIND_ASSIGN_VARIABLE: + case EXPR_KIND_VARIABLE_DEFAULT: result = false; break; @@ -632,6 +633,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) case EXPR_KIND_CYCLE_MARK: case EXPR_KIND_ASSIGN_VARIABLE: case EXPR_KIND_LET_TARGET: + case EXPR_KIND_VARIABLE_DEFAULT: /* okay */ break; @@ -2019,6 +2021,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink) break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_VARIABLE_DEFAULT: err = _("cannot use subquery in DEFAULT expression"); break; case EXPR_KIND_INDEX_EXPRESSION: @@ -3368,6 +3371,7 @@ ParseExprKindName(ParseExprKind exprKind) return "CHECK"; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_VARIABLE_DEFAULT: return "DEFAULT"; case EXPR_KIND_INDEX_EXPRESSION: return "index expression"; diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c index b6e780de93..abc27ab257 100644 --- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -2618,6 +2618,7 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location) break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_VARIABLE_DEFAULT: err = _("set-returning functions are not allowed in DEFAULT expressions"); break; case EXPR_KIND_INDEX_EXPRESSION: diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 53238fb746..201e28b685 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -4923,6 +4923,7 @@ getVariables(Archive *fout) int i_varnamespace; int i_vartype; int i_vartypname; + int i_vardefexpr; int i_vareoxaction; int i_varowner; int i_varcollation; @@ -4947,6 +4948,7 @@ getVariables(Archive *fout) "pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n" "CASE WHEN v.varcollation <> t.typcollation " "THEN v.varcollation ELSE 0 END AS varcollation,\n" + "pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n" "v.varowner,\n" "v.varacl,\n" "acldefault('V', v.varowner) AS acldefault\n" @@ -4964,6 +4966,7 @@ getVariables(Archive *fout) i_varnamespace = PQfnumber(res, "varnamespace"); i_vartype = PQfnumber(res, "vartype"); i_vartypname = PQfnumber(res, "vartypname"); + i_vardefexpr = PQfnumber(res, "vardefexpr"); i_vareoxaction = PQfnumber(res, "vareoxaction"); i_varcollation = PQfnumber(res, "varcollation"); @@ -5000,6 +5003,11 @@ getVariables(Archive *fout) /* Decide whether we want to dump it */ selectDumpableObject(&(varinfo[i].dobj), fout); + if (PQgetisnull(res, i, i_vardefexpr)) + varinfo[i].vardefexpr = NULL; + else + varinfo[i].vardefexpr = pg_strdup(PQgetvalue(res, i, i_vardefexpr)); + /* Do not try to dump ACL if no ACL exists. */ if (!PQgetisnull(res, i, i_varacl)) varinfo[i].dobj.components |= DUMP_COMPONENT_ACL; @@ -5032,6 +5040,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo) PQExpBuffer query; char *qualvarname; const char *vartypname; + const char *vardefexpr; const char *vareoxaction; Oid varcollation; @@ -5044,6 +5053,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo) qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo)); vartypname = varinfo->vartypname; + vardefexpr = varinfo->vardefexpr; vareoxaction = varinfo->vareoxaction; varcollation = varinfo->varcollation; @@ -5063,6 +5073,10 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo) fmtQualifiedDumpable(coll)); } + if (vardefexpr) + appendPQExpBuffer(query, " DEFAULT %s", + vardefexpr); + if (strcmp(vareoxaction, "r") == 0) appendPQExpBuffer(query, " ON TRANSACTION END RESET"); diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h index a42e1cff76..4a6b7bda13 100644 --- a/src/bin/pg_dump/pg_dump.h +++ b/src/bin/pg_dump/pg_dump.h @@ -677,6 +677,7 @@ typedef struct _VariableInfo DumpableAcl dacl; Oid vartype; char *vartypname; + char *vardefexpr; char *vareoxaction; char *varacl; char *rvaracl; diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl index 00b86d4971..2479891e54 100644 --- a/src/bin/pg_dump/t/002_pg_dump.pl +++ b/src/bin/pg_dump/t/002_pg_dump.pl @@ -3996,6 +3996,42 @@ my %tests = ( }, }, + 'CREATE VARIABLE test_variable DEFAULT' => { + all_runs => 1, + catch_all => 'CREATE ... commands', + create_order => 61, + create_sql => 'CREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;', + regexp => qr/^ + \QCREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;\E/xm, + like => { + %full_runs, + %dump_test_schema_runs, + section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + only_dump_measurement => 1, + }, + }, + + 'CREATE VARIABLE test_variable DEFAULT ON TRANSACTION END RESET' => { + all_runs => 1, + catch_all => 'CREATE ... commands', + create_order => 61, + create_sql => 'CREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET', + regexp => qr/^ + \QCREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET;\E/xm, + like => { + %full_runs, + %dump_test_schema_runs, + section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + only_dump_measurement => 1, + }, + }, + 'CREATE VIEW test_view' => { create_order => 61, create_sql => 'CREATE VIEW dump_test.test_view diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c index 397ed35a72..53e0d9f9fb 100644 --- a/src/bin/psql/describe.c +++ b/src/bin/psql/describe.c @@ -5097,7 +5097,7 @@ listVariables(const char *pattern, bool verbose) PQExpBufferData buf; PGresult *res; printQueryOpt myopt = pset.popt; - static const bool translate_columns[] = {false, false, false, false, false, false, false, false}; + static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false}; initPQExpBuffer(&buf); @@ -5108,6 +5108,7 @@ listVariables(const char *pattern, bool verbose) " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n" " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n" " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n" + " pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n" " CASE v.vareoxaction\n" " WHEN 'd' THEN 'ON COMMIT DROP'\n" " WHEN 'r' THEN 'ON TRANSACTION END RESET'\n" @@ -5117,6 +5118,7 @@ listVariables(const char *pattern, bool verbose) gettext_noop("Type"), gettext_noop("Collation"), gettext_noop("Owner"), + gettext_noop("Default"), gettext_noop("Transactional end action")); if (verbose) diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h index c10a9419cc..bb49a52948 100644 --- a/src/include/catalog/pg_variable.h +++ b/src/include/catalog/pg_variable.h @@ -66,6 +66,9 @@ CATALOG(pg_variable,9222,VariableRelationId) /* access permissions */ aclitem varacl[1] BKI_DEFAULT(_null_); + /* list of expression trees for variable default (NULL if none) */ + pg_node_tree vardefexpr BKI_DEFAULT(_null_); + #endif } FormData_pg_variable; diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 76295314df..c42de08e10 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -3285,6 +3285,7 @@ typedef struct CreateSessionVarStmt TypeName *typeName; /* the type of variable */ CollateClause *collClause; bool if_not_exists; /* do nothing if it already exists */ + Node *defexpr; /* default expression */ char eoxaction; /* on commit action */ } CreateSessionVarStmt; diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h index ad48d20663..a46069ed34 100644 --- a/src/include/parser/parse_node.h +++ b/src/include/parser/parse_node.h @@ -84,6 +84,7 @@ typedef enum ParseExprKind EXPR_KIND_ASSIGN_VARIABLE, /* PL/pgSQL assignment target - disallow * session variables */ EXPR_KIND_LET_TARGET, /* LET target */ + EXPR_KIND_VARIABLE_DEFAULT, /* default value for session variable */ } ParseExprKind; diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out index de572f7cf9..2624ce7ba1 100644 --- a/src/test/regress/expected/psql.out +++ b/src/test/regress/expected/psql.out @@ -5819,20 +5819,20 @@ CREATE ROLE regress_variable_owner; SET ROLE TO regress_variable_owner; CREATE VARIABLE var1 AS varchar COLLATE "C"; \dV+ var1 - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description ---------+------+-------------------+-----------+------------------------+--------------------------+-------------------+------------- - public | var1 | character varying | C | regress_variable_owner | | | + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description +--------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+------------- + public | var1 | character varying | C | regress_variable_owner | | | | (1 row) GRANT SELECT ON VARIABLE var1 TO PUBLIC; COMMENT ON VARIABLE var1 IS 'some description'; \dV+ var1 - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description ---------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------ - public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description - | | | | | | =r/regress_variable_owner | + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description +--------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------ + public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description + | | | | | | | =r/regress_variable_owner | (1 row) DROP VARIABLE var1; @@ -6300,9 +6300,9 @@ List of schemas (0 rows) \dV "no.such.variable" - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action ---------+------+------+-----------+-------+-------------------------- + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action +--------+------+------+-----------+-------+---------+-------------------------- (0 rows) -- again, but with dotted schema qualifications. @@ -6475,9 +6475,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta \dy "no.such.schema"."no.such.event.trigger" improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger" \dV "no.such.schema"."no.such.variable" - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action ---------+------+------+-----------+-------+-------------------------- + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action +--------+------+------+-----------+-------+---------+-------------------------- (0 rows) -- again, but with current database and dotted schema qualifications. @@ -6614,9 +6614,9 @@ List of text search templates (0 rows) \dV regression."no.such.schema"."no.such.variable" - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action ---------+------+------+-----------+-------+-------------------------- + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action +--------+------+------+-----------+-------+---------+-------------------------- (0 rows) -- again, but with dotted database and dotted schema qualifications. diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index d71c6adae8..7fb5b01fe8 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -45,11 +45,11 @@ SET ROLE TO regress_variable_owner; CREATE VARIABLE svartest.var1 AS int; SET ROLE TO DEFAULT; \dV+ svartest.var1 - List of variables - Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description -----------+------+---------+-----------+------------------------+--------------------------+--------------------------------------------------+------------- - svartest | var1 | integer | | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| - | | | | | | regress_variable_reader=r/regress_variable_owner | + List of variables + Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description +----------+------+---------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------- + svartest | var1 | integer | | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| + | | | | | | | regress_variable_reader=r/regress_variable_owner | (1 row) DROP VARIABLE svartest.var1; @@ -1390,3 +1390,66 @@ SELECT var1 IS NULL; (1 row) DROP VARIABLE var1; +CREATE OR REPLACE FUNCTION vartest_fx() +RETURNS int AS $$ +BEGIN + RAISE NOTICE 'vartest_fx executed'; + RETURN 0; +END; +$$ LANGUAGE plpgsql; +CREATE VARIABLE var1 AS int DEFAULT vartest_fx(); +-- vartest_fx should be protected by dep, should fail +DROP FUNCTION vartest_fx(); +ERROR: cannot drop function vartest_fx() because other objects depend on it +DETAIL: session variable var1 depends on function vartest_fx() +HINT: Use DROP ... CASCADE to drop the dependent objects too. +-- should be ok +SELECT var1; +NOTICE: vartest_fx executed + var1 +------ + 0 +(1 row) + +-- the defexpr should be evaluated only once +SELECT var1; + var1 +------ + 0 +(1 row) + +DISCARD VARIABLES; +-- in this case, the defexpr should not be evaluated +LET var1 = 100; +SELECT var1; + var1 +------ + 100 +(1 row) + +DISCARD VARIABLES; +CREATE OR REPLACE FUNCTION vartest_fx() +RETURNS int AS $$ +BEGIN + RAISE EXCEPTION 'vartest_fx is executing'; + RETURN 0; +END; +$$ LANGUAGE plpgsql; +-- should to fail, but not to crash +SELECT var1; +ERROR: vartest_fx is executing +CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE +-- again +SELECT var1; +ERROR: vartest_fx is executing +CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE +-- but we can write +LET var1 = 100; +SELECT var1; + var1 +------ + 100 +(1 row) + +DROP VARIABLE var1; +DROP FUNCTION vartest_fx(); diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index 25fda17ffd..afad65f999 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -889,3 +889,51 @@ ROLLBACK; SELECT var1 IS NULL; DROP VARIABLE var1; + +CREATE OR REPLACE FUNCTION vartest_fx() +RETURNS int AS $$ +BEGIN + RAISE NOTICE 'vartest_fx executed'; + RETURN 0; +END; +$$ LANGUAGE plpgsql; + +CREATE VARIABLE var1 AS int DEFAULT vartest_fx(); + +-- vartest_fx should be protected by dep, should fail +DROP FUNCTION vartest_fx(); + +-- should be ok +SELECT var1; + +-- the defexpr should be evaluated only once +SELECT var1; + +DISCARD VARIABLES; + +-- in this case, the defexpr should not be evaluated +LET var1 = 100; +SELECT var1; + +DISCARD VARIABLES; + +CREATE OR REPLACE FUNCTION vartest_fx() +RETURNS int AS $$ +BEGIN + RAISE EXCEPTION 'vartest_fx is executing'; + RETURN 0; +END; +$$ LANGUAGE plpgsql; + +-- should to fail, but not to crash +SELECT var1; + +-- again +SELECT var1; + +-- but we can write +LET var1 = 100; +SELECT var1; + +DROP VARIABLE var1; +DROP FUNCTION vartest_fx(); -- 2.41.0