Fix parallel-safety check of expressions and predicate for index builds As coded, the planner logic that calculates the number of parallel workers to use for a parallel index build uses expressions and predicates from the relcache, which are flattened for the planner by eval_const_expressions().
As reported in the bug, an immutable parallel-unsafe function flattened in the relcache would become a Const, which would be considered as parallel-safe, even if the predicate or the expressions including the function are not safe in parallel workers. Depending on the expressions or predicate used, this could cause the parallel build to fail. Tests are included that check parallel index builds with parallel-unsafe predicate and expressions. Two routines are added to lsyscache.h to be able to retrieve expressions and predicate of an index from its pg_index data. Reported-by: Alexander Lakhin Author: Tender Wang Reviewed-by: Jian He, Michael Paquier Discussion: https://postgr.es/m/CAHewXN=UaAaNn9ruHDH3Os8kxLVmtWqbssnf=dZN_s9=evh...@mail.gmail.com Backpatch-through: 12 Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/50b5913a87c9c2d67330d82429f6dda61441d40c Modified Files -------------- src/backend/optimizer/plan/planner.c | 12 +++++- src/backend/utils/cache/lsyscache.c | 68 +++++++++++++++++++++++++++++++ src/include/utils/lsyscache.h | 2 + src/test/regress/expected/btree_index.out | 19 +++++++++ src/test/regress/sql/btree_index.sql | 22 ++++++++++ 5 files changed, 121 insertions(+), 2 deletions(-)
