diff options
Diffstat (limited to 'src/backend/optimizer/plan/analyzejoins.c')
| -rw-r--r-- | src/backend/optimizer/plan/analyzejoins.c | 85 |
1 files changed, 52 insertions, 33 deletions
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c index c3fd4a81f8a..928d926645e 100644 --- a/src/backend/optimizer/plan/analyzejoins.c +++ b/src/backend/optimizer/plan/analyzejoins.c @@ -27,6 +27,7 @@ #include "optimizer/optimizer.h" #include "optimizer/pathnode.h" #include "optimizer/paths.h" +#include "optimizer/placeholder.h" #include "optimizer/planmain.h" #include "optimizer/restrictinfo.h" #include "utils/lsyscache.h" @@ -342,35 +343,6 @@ remove_rel_from_query(PlannerInfo *root, int relid, SpecialJoinInfo *sjinfo) joinrelids = bms_add_member(joinrelids, ojrelid); /* - * Remove references to the rel from other baserels' attr_needed arrays. - */ - for (rti = 1; rti < root->simple_rel_array_size; rti++) - { - RelOptInfo *otherrel = root->simple_rel_array[rti]; - int attroff; - - /* there may be empty slots corresponding to non-baserel RTEs */ - if (otherrel == NULL) - continue; - - Assert(otherrel->relid == rti); /* sanity check on array */ - - /* no point in processing target rel itself */ - if (otherrel == rel) - continue; - - for (attroff = otherrel->max_attr - otherrel->min_attr; - attroff >= 0; - attroff--) - { - otherrel->attr_needed[attroff] = - bms_del_member(otherrel->attr_needed[attroff], relid); - otherrel->attr_needed[attroff] = - bms_del_member(otherrel->attr_needed[attroff], ojrelid); - } - } - - /* * Update all_baserels and related relid sets. */ root->all_baserels = bms_del_member(root->all_baserels, relid); @@ -450,9 +422,11 @@ remove_rel_from_query(PlannerInfo *root, int relid, SpecialJoinInfo *sjinfo) phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, relid); phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, ojrelid); Assert(!bms_is_empty(phinfo->ph_eval_at)); /* checked previously */ - phinfo->ph_needed = bms_del_member(phinfo->ph_needed, relid); - phinfo->ph_needed = bms_del_member(phinfo->ph_needed, ojrelid); - /* ph_needed might or might not become empty */ + /* Reduce ph_needed to contain only "relation 0"; see below */ + if (bms_is_member(0, phinfo->ph_needed)) + phinfo->ph_needed = bms_make_singleton(0); + else + phinfo->ph_needed = NULL; phv->phrels = bms_del_member(phv->phrels, relid); phv->phrels = bms_del_member(phv->phrels, ojrelid); Assert(!bms_is_empty(phv->phrels)); @@ -540,7 +514,7 @@ remove_rel_from_query(PlannerInfo *root, int relid, SpecialJoinInfo *sjinfo) */ /* - * Finally, remove the rel from the baserel array to prevent it from being + * Now remove the rel from the baserel array to prevent it from being * referenced again. (We can't do this earlier because * remove_join_clause_from_rels will touch it.) */ @@ -548,6 +522,51 @@ remove_rel_from_query(PlannerInfo *root, int relid, SpecialJoinInfo *sjinfo) /* And nuke the RelOptInfo, just in case there's another access path */ pfree(rel); + + /* + * Finally, we must recompute per-Var attr_needed and per-PlaceHolderVar + * ph_needed relid sets. These have to be known accurately, else we may + * fail to remove other now-removable outer joins. And our removal of the + * join clause(s) for this outer join may mean that Vars that were + * formerly needed no longer are. So we have to do this honestly by + * repeating the construction of those relid sets. We can cheat to one + * small extent: we can avoid re-examining the targetlist and HAVING qual + * by preserving "relation 0" bits from the existing relid sets. This is + * safe because we'd never remove such references. + * + * So, start by removing all other bits from attr_needed sets. (We + * already did this above for ph_needed.) + */ + for (rti = 1; rti < root->simple_rel_array_size; rti++) + { + RelOptInfo *otherrel = root->simple_rel_array[rti]; + int attroff; + + /* there may be empty slots corresponding to non-baserel RTEs */ + if (otherrel == NULL) + continue; + + Assert(otherrel->relid == rti); /* sanity check on array */ + + for (attroff = otherrel->max_attr - otherrel->min_attr; + attroff >= 0; + attroff--) + { + if (bms_is_member(0, otherrel->attr_needed[attroff])) + otherrel->attr_needed[attroff] = bms_make_singleton(0); + else + otherrel->attr_needed[attroff] = NULL; + } + } + + /* + * Now repeat construction of attr_needed bits coming from all other + * sources. + */ + rebuild_placeholder_attr_needed(root); + rebuild_joinclause_attr_needed(root); + rebuild_eclass_attr_needed(root); + rebuild_lateral_attr_needed(root); } /* |