From d71906c77584a561bf51ac188a8ae65d76b4cbc6 Mon Sep 17 00:00:00 2001
From: Japin Li <japinli@hotmail.com>
Date: Thu, 16 May 2024 17:42:53 +0800
Subject: [PATCH v2] Push down FETCH FIRST WITH TIES to the remote side

---
 contrib/postgres_fdw/deparse.c                |  13 +-
 .../postgres_fdw/expected/postgres_fdw.out    | 113 ++++++++++++++++++
 contrib/postgres_fdw/sql/postgres_fdw.sql     |   2 +
 src/backend/parser/gram.y                     |   2 +
 4 files changed, 128 insertions(+), 2 deletions(-)

diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index fb590c87e6..a95fc2527f 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -4012,8 +4012,17 @@ appendLimitClause(deparse_expr_cxt *context)
 
 	if (root->parse->limitCount)
 	{
-		appendStringInfoString(buf, " LIMIT ");
-		deparseExpr((Expr *) root->parse->limitCount, context);
+		if (root->parse->limitOption == LIMIT_OPTION_WITH_TIES)
+		{
+			appendStringInfoString(buf, " FETCH FIRST ");
+			deparseExpr((Expr *) root->parse->limitCount, context);
+			appendStringInfoString(buf, " ROWS WITH TIES");
+		}
+		else
+		{
+			appendStringInfoString(buf, " LIMIT ");
+			deparseExpr((Expr *) root->parse->limitCount, context);
+		}
 	}
 	if (root->parse->limitOffset)
 	{
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 078b8a966f..d350d1bdf4 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -339,6 +339,119 @@ SELECT t1 FROM ft1 t1 ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
  (110,0,00110,"Sun Jan 11 00:00:00 1970 PST","Sun Jan 11 00:00:00 1970",0,"0         ",foo)
 (10 rows)
 
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 ORDER BY t1.c2 FETCH FIRST 2 ROWS WITH TIES;
+                                                               QUERY PLAN                                                                
+-----------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan on public.ft1 t1
+   Output: c1, c2, c3, c4, c5, c6, c7, c8
+   Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c2 ASC NULLS LAST FETCH FIRST 2::bigint ROWS WITH TIES
+(3 rows)
+
+SELECT * FROM ft1 t1 ORDER BY t1.c2 FETCH FIRST 2 ROWS WITH TIES;
+  c1  | c2 |  c3   |              c4              |            c5            | c6 |     c7     | c8  
+------+----+-------+------------------------------+--------------------------+----+------------+-----
+ 1000 |  0 | 01000 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  200 |  0 | 00200 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  190 |  0 | 00190 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  180 |  0 | 00180 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  170 |  0 | 00170 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  160 |  0 | 00160 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  150 |  0 | 00150 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  140 |  0 | 00140 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  130 |  0 | 00130 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  110 |  0 | 00110 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  920 |  0 | 00920 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  120 |  0 | 00120 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  910 |  0 | 00910 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  900 |  0 | 00900 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  890 |  0 | 00890 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  880 |  0 | 00880 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  870 |  0 | 00870 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  860 |  0 | 00860 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  850 |  0 | 00850 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+   20 |  0 | 00020 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  990 |  0 | 00990 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  840 |  0 | 00840 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  830 |  0 | 00830 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  820 |  0 | 00820 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  810 |  0 | 00810 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  800 |  0 | 00800 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  790 |  0 | 00790 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  780 |  0 | 00780 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  770 |  0 | 00770 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+   30 |  0 | 00030 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  980 |  0 | 00980 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  760 |  0 | 00760 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  750 |  0 | 00750 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  740 |  0 | 00740 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  730 |  0 | 00730 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  720 |  0 | 00720 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  710 |  0 | 00710 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  700 |  0 | 00700 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  690 |  0 | 00690 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+   40 |  0 | 00040 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  970 |  0 | 00970 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  680 |  0 | 00680 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  670 |  0 | 00670 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  660 |  0 | 00660 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  650 |  0 | 00650 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  640 |  0 | 00640 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  630 |  0 | 00630 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  620 |  0 | 00620 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  610 |  0 | 00610 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+   50 |  0 | 00050 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  960 |  0 | 00960 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  600 |  0 | 00600 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  590 |  0 | 00590 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  580 |  0 | 00580 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  570 |  0 | 00570 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  560 |  0 | 00560 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  550 |  0 | 00550 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  540 |  0 | 00540 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  530 |  0 | 00530 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+   60 |  0 | 00060 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  950 |  0 | 00950 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  520 |  0 | 00520 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  510 |  0 | 00510 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  500 |  0 | 00500 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  490 |  0 | 00490 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  480 |  0 | 00480 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  470 |  0 | 00470 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  460 |  0 | 00460 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  450 |  0 | 00450 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+   70 |  0 | 00070 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  940 |  0 | 00940 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  440 |  0 | 00440 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  430 |  0 | 00430 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  420 |  0 | 00420 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  410 |  0 | 00410 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  400 |  0 | 00400 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  390 |  0 | 00390 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+  380 |  0 | 00380 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  370 |  0 | 00370 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+   80 |  0 | 00080 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  930 |  0 | 00930 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  360 |  0 | 00360 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  350 |  0 | 00350 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  340 |  0 | 00340 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  330 |  0 | 00330 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  320 |  0 | 00320 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  310 |  0 | 00310 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  300 |  0 | 00300 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+  290 |  0 | 00290 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+   90 |  0 | 00090 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo
+   10 |  0 | 00010 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  280 |  0 | 00280 | Sun Mar 22 00:00:00 1970 PST | Sun Mar 22 00:00:00 1970 | 0  | 0          | foo
+  270 |  0 | 00270 | Thu Mar 12 00:00:00 1970 PST | Thu Mar 12 00:00:00 1970 | 0  | 0          | foo
+  260 |  0 | 00260 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo
+  250 |  0 | 00250 | Fri Feb 20 00:00:00 1970 PST | Fri Feb 20 00:00:00 1970 | 0  | 0          | foo
+  240 |  0 | 00240 | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0  | 0          | foo
+  230 |  0 | 00230 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo
+  220 |  0 | 00220 | Wed Jan 21 00:00:00 1970 PST | Wed Jan 21 00:00:00 1970 | 0  | 0          | foo
+  210 |  0 | 00210 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0  | 0          | foo
+  100 |  0 | 00100 | Thu Jan 01 00:00:00 1970 PST | Thu Jan 01 00:00:00 1970 | 0  | 0          | foo
+(100 rows)
+
 -- empty result
 SELECT * FROM ft1 WHERE false;
  c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 09ba234e43..ca8778d00d 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -265,6 +265,8 @@ SELECT * FROM ft1 t1 ORDER BY t1.c3, t1.c1, t1.tableoid OFFSET 100 LIMIT 10;
 -- whole-row reference
 EXPLAIN (VERBOSE, COSTS OFF) SELECT t1 FROM ft1 t1 ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
 SELECT t1 FROM ft1 t1 ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 ORDER BY t1.c2 FETCH FIRST 2 ROWS WITH TIES;
+SELECT * FROM ft1 t1 ORDER BY t1.c2 FETCH FIRST 2 ROWS WITH TIES;
 -- empty result
 SELECT * FROM ft1 WHERE false;
 -- with WHERE clause
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4d582950b7..4494410fec 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -13292,6 +13292,8 @@ select_offset_value:
  */
 select_fetch_first_value:
 			c_expr									{ $$ = $1; }
+			| a_expr TYPECAST Typename
+				{ $$ = makeTypeCast($1, $3, @2); }
 			| '+' I_or_F_const
 				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "+", NULL, $2, @1); }
 			| '-' I_or_F_const
-- 
2.41.0