pgsql-server/src backend/optimizer/path/allpat ...

CVSROOT: /cvsroot
Module name: pgsql-server
Changes by: tgl(at)postgresql(dot)org 03/03/21 20:49:38

Modified files:
src/backend/optimizer/path: allpaths.c
src/backend/optimizer/util: clauses.c
src/backend/parser: parse_clause.c
src/include/parser: parse_clause.h

Log message:
Adjust subquery qual pushdown rules to be more forgiving: if a qual
refers to a non-DISTINCT output column of a DISTINCT ON subquery, or
if it refers to a function-returning-set, we cannot push it down.
But the old implementation refused to push down *any* quals if the
subquery had any such 'dangerous' outputs. Now we just look at the
output columns actually referenced by each qual expression. More code
than before, but probably no slower since we don't make unnecessary checks.