Make real sure we don't reassociate joins into or out of SEMI/ANTI joins. Per the discussion in optimizer/README, it's unsafe to reassociate anything into or out of the RHS of a SEMI or ANTI join. An example from Piotr Stefaniak showed that join_is_legal() wasn't sufficiently enforcing this rule, so lock it down a little harder.
I couldn't find a reasonably simple example of the optimizer trying to do this, so no new regression test. (Piotr's example involved the random search in GEQO accidentally trying an invalid case and triggering a sanity check way downstream in clause selectivity estimation, which did not seem like a sequence of events that would be useful to memorialize in a regression test as-is.) Back-patch to all active branches. Branch ------ REL9_0_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/c084f613e20165012974db44106e4c5174c2ba5f Modified Files -------------- src/backend/optimizer/path/joinrels.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
