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. Branch ------ REL_10_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/39862dde4beecdf1c5f84a20fe3bb6f4ba928edb Modified Files -------------- 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(-)
