postgres.git / summary / log / commit / refs
commit 39862dde4beecdf1c5f84a20fe3bb6f4ba928edb
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue Jun 01 15:12:56 2021 +0000
First released in: 14.0, 9.6.23, 10.18, 11.13, 12.8, 13.4
Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.
This case should be disallowed, just as FOR UPDATE with a plain
GROUP BY is disallowed; FOR UPDATE only makes sense when each row
of the query result can be identified with a single table row.
However, we missed teaching CheckSelectLocking() to check
groupingSets as well as groupClause, so that it would allow
degenerate grouping sets. That resulted in a bad plan and
a null-pointer dereference in the executor.
Looking around for other instances of the same bug, the only one
I found was in examine_simple_variable(). That'd just lead to
silly estimates, but it should be fixed too.
Per private report from Yaoguang Chen.
Back-patch to all supported branches.
src/backend/parser/analyze.c | 2 +-
src/backend/utils/adt/selfuncs.c | 3 ++-
src/test/regress/expected/errors.out | 5 +++++
src/test/regress/sql/errors.sql | 4 ++++
4 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 7854078f99b..9fc0818d3df 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2653,7 +2653,7 @@ CheckSelectLocking(Query *qry, LockClauseStrength strength)
translator: %s is a SQL row locking clause such as FOR UPDATE */
errmsg("%s is not allowed with DISTINCT clause",
LCS_asString(strength))));
- if (qry->groupClause != NIL)
+ if (qry->groupClause != NIL || qry->groupingSets != NIL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
/*------
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c2f5f948b06..6a7d6b4e871 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4920,7 +4920,8 @@ examine_simple_variable(PlannerInfo *root, Var *var,
* of learning something even with it.
*/
if (subquery->setOperations ||
- subquery->groupClause)
+ subquery->groupClause ||
+ subquery->groupingSets)
return;
/*
diff --git a/src/test/regress/expected/errors.out b/src/test/regress/expected/errors.out
index ce473a03efd..cc1cdc0dd02 100644
--- a/src/test/regress/expected/errors.out
+++ b/src/test/regress/expected/errors.out
@@ -50,6 +50,11 @@ select distinct on (foobar) * from pg_database;
ERROR: column "foobar" does not exist
LINE 1: select distinct on (foobar) * from pg_database;
^
+-- grouping with FOR UPDATE
+select null from pg_database group by datname for update;
+ERROR: FOR UPDATE is not allowed with GROUP BY clause
+select null from pg_database group by grouping sets (()) for update;
+ERROR: FOR UPDATE is not allowed with GROUP BY clause
--
-- DELETE
-- missing relation name (this had better not wildcard!)
diff --git a/src/test/regress/sql/errors.sql b/src/test/regress/sql/errors.sql
index 14bc723a52a..9444a5d48f3 100644
--- a/src/test/regress/sql/errors.sql
+++ b/src/test/regress/sql/errors.sql
@@ -37,6 +37,10 @@ select * from pg_database where pg_database.datname = nonesuch;
-- bad attribute name in select distinct on
select distinct on (foobar) * from pg_database;
+-- grouping with FOR UPDATE
+select null from pg_database group by datname for update;
+select null from pg_database group by grouping sets (()) for update;
+
--
-- DELETE
[parent: f9e35ff236c9]