[PATCH]: ./revert-a3179ab69-doesnt-work.patch

Author: Commitfest Bot

src/backend/optimizer/path/equivclass.c

@@ -1453,8 +1453,7 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 	 * For the moment we force all the Vars to be available at all join nodes
 	 * for this eclass.  Perhaps this could be improved by doing some
 	 * pre-analysis of which members we prefer to join, but it's no worse than
-	 * what happened in the pre-8.3 code.  (Note: rebuild_eclass_attr_needed
-	 * needs to match this code.)
+	 * what happened in the pre-8.3 code.
 	 */
 	foreach(lc, ec->ec_members)
 	{
@@ -2561,51 +2560,6 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 	return false;				/* failed to make any deduction */
 }
 
-/*
- * rebuild_eclass_attr_needed
- *	  Put back attr_needed bits for Vars/PHVs needed for join eclasses.
- *
- * This is used to rebuild attr_needed/ph_needed sets after removal of a
- * useless outer join.  It should match what
- * generate_base_implied_equalities_no_const did, except that we call
- * add_vars_to_attr_needed not add_vars_to_targetlist.
- */
-void
-rebuild_eclass_attr_needed(PlannerInfo *root)
-{
-	ListCell   *lc;
-
-	foreach(lc, root->eq_classes)
-	{
-		EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc);
-
-		/*
-		 * We don't expect any EC child members to exist at this point. Ensure
-		 * that's the case, otherwise, we might be getting asked to do
-		 * something this function hasn't been coded for.
-		 */
-		Assert(ec->ec_childmembers == NULL);
-
-		/* Need do anything only for a multi-member, no-const EC. */
-		if (list_length(ec->ec_members) > 1 && !ec->ec_has_const)
-		{
-			ListCell   *lc2;
-
-			foreach(lc2, ec->ec_members)
-			{
-				EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
-				List	   *vars = pull_var_clause((Node *) cur_em->em_expr,
-												   PVC_RECURSE_AGGREGATES |
-												   PVC_RECURSE_WINDOWFUNCS |
-												   PVC_INCLUDE_PLACEHOLDERS);
-
-				add_vars_to_attr_needed(root, vars, ec->ec_relids);
-				list_free(vars);
-			}
-		}
-	}
-}
-
 /*
  * find_join_domain
  *	  Find the highest JoinDomain enclosed within the given relid set.

src/backend/optimizer/plan/analyzejoins.c

@@ -28,7 +28,6 @@
 #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 "rewrite/rewriteManip.h"
@@ -344,6 +343,37 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 											  sjinfo->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);
+			if (sjinfo != NULL)
+				otherrel->attr_needed[attroff] =
+					bms_del_member(otherrel->attr_needed[attroff],
+								   sjinfo->ojrelid);
+		}
+	}
+
 	/*
 	 * Likewise remove references from SpecialJoinInfo data structures.
 	 *
@@ -451,11 +481,13 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 				phinfo->ph_eval_at = adjust_relid_set(phinfo->ph_eval_at,
 													  sjinfo->ojrelid, subst);
 			Assert(!bms_is_empty(phinfo->ph_eval_at));	/* checked previously */
-			/* 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;
+
+			phinfo->ph_needed = adjust_relid_set(phinfo->ph_needed,
+												 relid, subst);
+			if (sjinfo != NULL)
+				phinfo->ph_needed = adjust_relid_set(phinfo->ph_needed,
+													 sjinfo->ojrelid, subst);
+			/* ph_needed might or might not become empty */
 
 			phinfo->ph_lateral = adjust_relid_set(phinfo->ph_lateral, relid, subst);
 
@@ -490,46 +522,6 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 			(sjinfo == NULL || bms_is_member(sjinfo->ojrelid, ec->ec_relids)))
 			remove_rel_from_eclass(ec, sjinfo, relid, subst);
 	}
-
-	/*
-	 * 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 and
-	 * lateral_vars lists.  (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;
-		}
-
-		if (subst > 0)
-			ChangeVarNodesExtended((Node *) otherrel->lateral_vars, relid,
-								   subst, 0, replace_relid_callback);
-	}
 }
 
 /*
@@ -626,7 +618,7 @@ remove_leftjoinrel_from_query(PlannerInfo *root, int relid,
 	 */
 
 	/*
-	 * Now remove the rel from the baserel array to prevent it from being
+	 * Finally, 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.)
 	 */
@@ -635,15 +627,6 @@ remove_leftjoinrel_from_query(PlannerInfo *root, int relid,
 
 	/* And nuke the RelOptInfo, just in case there's another access path */
 	pfree(rel);
-
-	/*
-	 * 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);
 }
 
 /*
@@ -1983,16 +1966,6 @@ remove_self_join_rel(PlannerInfo *root, PlanRowMark *kmark, PlanRowMark *rmark,
 
 	/* And nuke the RelOptInfo, just in case there's another access path. */
 	pfree(toRemove);
-
-
-	/*
-	 * 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);
 }
 
 /*