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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2023-12-25 01:24:25 +0200 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2023-12-25 01:33:26 +0200 |
| commit | b5fb6736ed3b6875e2a4ca39d33325147f535137 (patch) | |
| tree | 3d5e2ebf0170d00316542ad5da52bc08cad19643 /src/backend/optimizer | |
| parent | 8a8ed916f73f4f16e8eb3e0e30ac1201a7642fda (diff) | |
| download | postgresql-b5fb6736ed3b6875e2a4ca39d33325147f535137.tar.gz postgresql-b5fb6736ed3b6875e2a4ca39d33325147f535137.zip | |
Don't constrain self-join removal due to PHVs
Self-join removal appears to be safe to apply with placeholder variables
as long as we handle PlaceHolderVar in replace_varno_walker() and replace
relid in phinfo->ph_lateral.
Discussion: https://postgr.es/m/18187-831da249cbd2ff8e%40postgresql.org
Author: Richard Guo
Reviewed-by: Andrei Lepikhov
Diffstat (limited to 'src/backend/optimizer')
| -rw-r--r-- | src/backend/optimizer/plan/analyzejoins.c | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c index 00404a8beb0..c328cbdb8d3 100644 --- a/src/backend/optimizer/plan/analyzejoins.c +++ b/src/backend/optimizer/plan/analyzejoins.c @@ -453,7 +453,7 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel, { PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l); - Assert(!bms_is_member(relid, phinfo->ph_lateral)); + Assert(sjinfo == NULL || !bms_is_member(relid, phinfo->ph_lateral)); if (bms_is_subset(phinfo->ph_needed, joinrelids) && bms_is_member(relid, phinfo->ph_eval_at) && !bms_is_member(ojrelid, phinfo->ph_eval_at)) @@ -472,6 +472,8 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel, phinfo->ph_needed = replace_relid(phinfo->ph_needed, relid, subst); phinfo->ph_needed = replace_relid(phinfo->ph_needed, ojrelid, subst); /* ph_needed might or might not become empty */ + phinfo->ph_lateral = replace_relid(phinfo->ph_lateral, relid, subst); + /* ph_lateral might or might not be empty */ phv->phrels = replace_relid(phv->phrels, relid, subst); phv->phrels = replace_relid(phv->phrels, ojrelid, subst); Assert(!bms_is_empty(phv->phrels)); @@ -2115,20 +2117,8 @@ remove_self_joins_one_group(PlannerInfo *root, Relids relids) joinrelids = bms_add_member(joinrelids, k); /* - * Be safe to do not remove tables participated in complicated PH + * PHVs should not impose any constraints on removing self joins. */ - foreach(lc, root->placeholder_list) - { - PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc); - - /* there isn't any other place to eval PHV */ - if (bms_is_subset(phinfo->ph_eval_at, joinrelids) || - bms_is_subset(phinfo->ph_needed, joinrelids) || - bms_is_member(r, phinfo->ph_lateral)) - break; - } - if (lc) - continue; /* * At this stage, joininfo lists of inner and outer can contain |