diff options
Diffstat (limited to 'src/backend/optimizer/plan/analyzejoins.c')
| -rw-r--r-- | src/backend/optimizer/plan/analyzejoins.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c index 97f8839ff2c..2a913578eba 100644 --- a/src/backend/optimizer/plan/analyzejoins.c +++ b/src/backend/optimizer/plan/analyzejoins.c @@ -26,6 +26,7 @@ #include "optimizer/pathnode.h" #include "optimizer/paths.h" #include "optimizer/planmain.h" +#include "optimizer/var.h" /* local functions */ static bool join_is_removable(PlannerInfo *root, SpecialJoinInfo *sjinfo); @@ -197,16 +198,23 @@ join_is_removable(PlannerInfo *root, SpecialJoinInfo *sjinfo) } /* - * Similarly check that the inner rel doesn't produce any PlaceHolderVars - * that will be used above the join. + * Similarly check that the inner rel isn't needed by any PlaceHolderVars + * that will be used above the join. We only need to fail if such a PHV + * actually references some inner-rel attributes; but the correct check + * for that is relatively expensive, so we first check against ph_eval_at, + * which must mention the inner rel if the PHV uses any inner-rel attrs. */ foreach(l, root->placeholder_list) { PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l); - if (bms_is_subset(phinfo->ph_eval_at, innerrel->relids) && - !bms_is_subset(phinfo->ph_needed, joinrelids)) - return false; + if (bms_is_subset(phinfo->ph_needed, joinrelids)) + continue; /* PHV is not used above the join */ + if (!bms_overlap(phinfo->ph_eval_at, innerrel->relids)) + continue; /* it definitely doesn't reference innerrel */ + if (bms_overlap(pull_varnos((Node *) phinfo->ph_var), + innerrel->relids)) + return false; /* it does reference innerrel */ } /* |