Thread: pgsql: Fix usage of the parse tree for estimate_num_groups() in set ope
pgsql: Fix usage of the parse tree for estimate_num_groups() in set ope
From
Alexander Korotkov
Date:
Fix usage of the parse tree for estimate_num_groups() in set operations recurse_set_operations() uses the parse tree for the group number estimation, because of the "varno 0" hack. At the same time 2489d76c49 made root->parse and corresponding parent_root->simple_rte_array[]->subquery distinct copies of the parse tree, while d3d55ce571 introduced self-join removal replacing relid of removed relation only in one of the copies. The present commit fixes this bug by making recurse_set_operations() call estimate_num_groups() with the copy of the parse tree processed by self-join removal. In future, we may think about maintaining just one copy of the parse tree and/or keeping removed relids as aliases. Reported-by: Zuming Jiang Bug: #18170 Discussion: https://postgr.es/m/flat/18170-f1d17bf9a0d58b24%40postgresql.org Author: Richard Guo, Alexander Korotkov Reviewed-by: Andrei Lepikhov Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/ec63622c03ff7be36d32c08aaa7d853856451488 Modified Files -------------- src/backend/optimizer/prep/prepunion.c | 7 +++++-- src/test/regress/expected/join.out | 17 +++++++++++++++++ src/test/regress/sql/join.sql | 7 +++++++ 3 files changed, 29 insertions(+), 2 deletions(-)