From e217dc7484e5e46f4b9bcef1e1bb03acc4a1834a Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 14 Jan 2026 08:44:12 +0900 Subject: [PATCH] Fix query jumbling with GROUP BY clauses RangeTblEntry.groupexprs was marked with the node attribute query_jumble_ignore, causing a list of GROUP BY expressions to be ignored during the query jumbling. For example, these two queries could be grouped together within the same query ID: SELECT count(*) FROM t GROUP BY a; SELECT count(*) FROM t GROUP BY b; However, as such queries use different GROUP BY clauses, they should be split across multiple entries. This fixes an oversight in 247dea89f761, that has introduced an RTE for GROUP BY clauses. Query IDs are documented as being stable across minor releases, but as this is a regression new to v18 and that we are still early in its support cycle, a backpatch is exceptionally done as this has broken a behavior that exists since query jumbling is supported in core, since its introduction in pg_stat_statements. The tests of pg_stat_statements are expanded to cover this area, with patterns involving GROUP BY and GROUPING clauses. Author: Jian He Discussion: https://postgr.es/m/CACJufxEy2W+tCqC7XuJ94r3ivWsM=onKJp94kRFx3hoARjBeFQ@mail.gmail.com Backpatch-through: 18 --- .../pg_stat_statements/expected/select.out | 98 ++++++++++++++++++- contrib/pg_stat_statements/sql/select.sql | 16 +++ src/include/nodes/parsenodes.h | 2 +- 3 files changed, 114 insertions(+), 2 deletions(-) diff --git a/contrib/pg_stat_statements/expected/select.out b/contrib/pg_stat_statements/expected/select.out index 75c896f3885..a069119c790 100644 --- a/contrib/pg_stat_statements/expected/select.out +++ b/contrib/pg_stat_statements/expected/select.out @@ -459,6 +459,102 @@ SELECT COUNT(*) FROM pg_stat_statements WHERE query LIKE '%FETCH FIRST%'; 2 (1 row) +-- GROUP BY, HAVING, GROUPING +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a; + count +------- + 1 +(1 row) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b; + count +------- + 1 +(1 row) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a, b; + count +------- + 1 +(1 row) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b, a; + count +------- + 1 +(1 row) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY GROUPING SETS(a, ()); + count +------- + 1 + 1 +(2 rows) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY GROUPING SETS(b, ()); + count +------- + 1 + 1 +(2 rows) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a HAVING a = 1; + count +------- + 1 +(1 row) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a HAVING a = 2; + count +------- +(0 rows) + +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b HAVING b = 1; + count +------- +(0 rows) + +SELECT GROUPING(a) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a; + grouping +---------- + 0 +(1 row) + +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b; + grouping +---------- + 0 +(1 row) + +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a, b; + grouping +---------- + 0 +(1 row) + +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b, a; + grouping +---------- + 0 +(1 row) + +SELECT calls, query FROM pg_stat_statements WHERE query LIKE '%GROUP BY%' ORDER BY query COLLATE "C"; + calls | query +-------+------------------------------------------------------------------------------------------- + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY GROUPING SETS(a, ()) + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY GROUPING SETS(b, ()) + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY a + 2 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY a HAVING a = $3 + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY a, b + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY b + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY b HAVING b = $3 + 1 | SELECT COUNT(*) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY b, a + 1 | SELECT GROUPING(a) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY a + 1 | SELECT GROUPING(b) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY a, b + 1 | SELECT GROUPING(b) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY b + 1 | SELECT GROUPING(b) FROM (VALUES ($1::INT, $2::INT)) AS t(a, b) GROUP BY b, a +(12 rows) + -- GROUP BY [DISTINCT] SELECT a, b, c FROM (VALUES (1, 2, 3), (4, NULL, 6), (7, 8, 9)) AS t (a, b, c) @@ -548,7 +644,7 @@ SELECT ( SELECT COUNT(*) FROM pg_stat_statements WHERE query LIKE '%SELECT GROUPING%'; count ------- - 2 + 6 (1 row) SELECT pg_stat_statements_reset() IS NOT NULL AS t; diff --git a/contrib/pg_stat_statements/sql/select.sql b/contrib/pg_stat_statements/sql/select.sql index 11662cde08c..a10d618c034 100644 --- a/contrib/pg_stat_statements/sql/select.sql +++ b/contrib/pg_stat_statements/sql/select.sql @@ -158,6 +158,22 @@ FETCH FIRST 2 ROW ONLY; SELECT COUNT(*) FROM pg_stat_statements WHERE query LIKE '%FETCH FIRST%'; +-- GROUP BY, HAVING, GROUPING +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a, b; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b, a; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY GROUPING SETS(a, ()); +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY GROUPING SETS(b, ()); +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a HAVING a = 1; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a HAVING a = 2; +SELECT COUNT(*) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b HAVING b = 1; +SELECT GROUPING(a) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a; +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b; +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY a, b; +SELECT GROUPING(b) FROM (VALUES (1::INT, 2::INT)) AS t(a, b) GROUP BY b, a; +SELECT calls, query FROM pg_stat_statements WHERE query LIKE '%GROUP BY%' ORDER BY query COLLATE "C"; + -- GROUP BY [DISTINCT] SELECT a, b, c FROM (VALUES (1, 2, 3), (4, NULL, 6), (7, 8, 9)) AS t (a, b, c) diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index aac4bfc70d9..646d6ced763 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -1294,7 +1294,7 @@ typedef struct RangeTblEntry * Fields valid for a GROUP RTE (else NIL): */ /* list of grouping expressions */ - List *groupexprs pg_node_attr(query_jumble_ignore); + List *groupexprs; /* * Fields valid in all RTEs: