diff options
Diffstat (limited to 'src/backend/optimizer/plan/initsplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/initsplan.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c index 9999eea4991..1a1c26adce8 100644 --- a/src/backend/optimizer/plan/initsplan.c +++ b/src/backend/optimizer/plan/initsplan.c @@ -1176,9 +1176,32 @@ make_outerjoininfo(PlannerInfo *root, { SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l); - /* ignore full joins --- other mechanisms preserve their ordering */ + /* + * A full join is an optimization barrier: we can't associate into or + * out of it. Hence, if it overlaps either LHS or RHS of the current + * rel, expand that side's min relset to cover the whole full join. + */ if (otherinfo->jointype == JOIN_FULL) + { + if (bms_overlap(left_rels, otherinfo->syn_lefthand) || + bms_overlap(left_rels, otherinfo->syn_righthand)) + { + min_lefthand = bms_add_members(min_lefthand, + otherinfo->syn_lefthand); + min_lefthand = bms_add_members(min_lefthand, + otherinfo->syn_righthand); + } + if (bms_overlap(right_rels, otherinfo->syn_lefthand) || + bms_overlap(right_rels, otherinfo->syn_righthand)) + { + min_righthand = bms_add_members(min_righthand, + otherinfo->syn_lefthand); + min_righthand = bms_add_members(min_righthand, + otherinfo->syn_righthand); + } + /* Needn't do anything else with the full join */ continue; + } /* * For a lower OJ in our LHS, if our join condition uses the lower |