From: Michael Paquier <michael@paquier.xyz>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix query jumbling with GROUP BY clauses
Date: Tue, 13 Jan 2026 23:52:11 +0000
Message-ID: <E1vfoBH-000JnJ-06@gemulon.postgresql.org> (raw)
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 <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxEy2W+tCqC7XuJ94r3ivWsM=onKJp94kRFx3hoARjBeFQ@mail.gmail.com
Backpatch-through: 18
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/9c3caad0264011490134816b2264de7f20b2eb99
Modified Files
--------------
contrib/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(-)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: michael@paquier.xyz, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix query jumbling with GROUP BY clauses
In-Reply-To: <E1vfoBH-000JnJ-06@gemulon.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox