diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/path/joinrels.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c index 3d4bc2530c5..6504ec07baa 100644 --- a/src/backend/optimizer/path/joinrels.c +++ b/src/backend/optimizer/path/joinrels.c @@ -462,10 +462,14 @@ join_is_legal(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, /* * Otherwise, the proposed join overlaps the RHS but isn't a valid * implementation of this SJ. It might still be a legal join, - * however, if it does not overlap the LHS. + * however, if it does not overlap the LHS. But we never allow + * violations of the RHS of SEMI or ANTI joins. (In practice, + * therefore, only LEFT joins ever allow RHS violation.) */ - if (bms_overlap(joinrelids, sjinfo->min_lefthand)) - return false; + if (sjinfo->jointype == JOIN_SEMI || + sjinfo->jointype == JOIN_ANTI || + bms_overlap(joinrelids, sjinfo->min_lefthand)) + return false; /* invalid join path */ /*---------- * If both inputs overlap the RHS, assume that it's OK. Since the @@ -490,15 +494,14 @@ join_is_legal(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, * Set flag here to check at bottom of loop. *---------- */ - if (sjinfo->jointype != JOIN_SEMI && - bms_overlap(rel1->relids, sjinfo->min_righthand) && + if (bms_overlap(rel1->relids, sjinfo->min_righthand) && bms_overlap(rel2->relids, sjinfo->min_righthand)) { /* both overlap; assume OK */ } else { - /* one overlaps, the other doesn't (or it's a semijoin) */ + /* one overlaps, the other doesn't */ is_valid_inner = false; } } |