Plug some more memory leaks in the planner. It still leaks like a sieve,

but this is as good as it'll get for this release...

src/backend/optimizer/path/joinpath.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.52 2000/02/15 20:49:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.53 2000/02/18 23:47:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -171,9 +171,13 @@ sort_inner_and_outer(Query *root,
 		List		   *merge_pathkeys;
 
 		/* Make a mergeclause list with this guy first. */
-		curclause_list = lcons(restrictinfo,
+		if (i != mergeclause_list)
-							   lremove(restrictinfo,
+			curclause_list = lcons(restrictinfo,
-									   listCopy(mergeclause_list)));
+								   lremove(restrictinfo,
+										   listCopy(mergeclause_list)));
+		else
+			curclause_list = mergeclause_list; /* no work at first one... */
+
 		/* Build sort pathkeys for both sides.
 		 *
 		 * Note: it's possible that the cheapest paths will already be
@@ -203,7 +207,7 @@ sort_inner_and_outer(Query *root,
 									   innerrel->cheapest_total_path,
 									   restrictlist,
 									   merge_pathkeys,
-									   get_actual_clauses(curclause_list),
+									   curclause_list,
 									   outerkeys,
 									   innerkeys));
 	}
@@ -265,6 +269,7 @@ match_unsorted_outer(Query *root,
 		List	   *trialsortkeys;
 		Path	   *cheapest_startup_inner;
 		Path	   *cheapest_total_inner;
+		int			num_mergeclauses;
 		int			clausecnt;
 
 		/*
@@ -325,7 +330,7 @@ match_unsorted_outer(Query *root,
 									   innerrel->cheapest_total_path,
 									   restrictlist,
 									   merge_pathkeys,
-									   get_actual_clauses(mergeclauses),
+									   mergeclauses,
 									   NIL,
 									   innersortkeys));
 
@@ -337,10 +342,12 @@ match_unsorted_outer(Query *root,
 		trialsortkeys = listCopy(innersortkeys); /* modifiable copy */
 		cheapest_startup_inner = NULL;
 		cheapest_total_inner = NULL;
+		num_mergeclauses = length(mergeclauses);
 
-		for (clausecnt = length(mergeclauses); clausecnt > 0; clausecnt--)
+		for (clausecnt = num_mergeclauses; clausecnt > 0; clausecnt--)
 		{
 			Path	   *innerpath;
+			List	   *newclauses = NIL;
 
 			/* Look for an inner path ordered well enough to merge with
 			 * the first 'clausecnt' mergeclauses.  NB: trialsortkeys list
@@ -356,10 +363,11 @@ match_unsorted_outer(Query *root,
 									TOTAL_COST) < 0))
 			{
 				/* Found a cheap (or even-cheaper) sorted path */
-				List   *newclauses;
+				if (clausecnt < num_mergeclauses)
-
+					newclauses = ltruncate(clausecnt,
-				newclauses = ltruncate(clausecnt,
+										   listCopy(mergeclauses));
-									   get_actual_clauses(mergeclauses));
+				else
+					newclauses = mergeclauses;
 				add_path(joinrel, (Path *)
 						 create_mergejoin_path(joinrel,
 											   outerpath,
@@ -383,10 +391,17 @@ match_unsorted_outer(Query *root,
 				/* Found a cheap (or even-cheaper) sorted path */
 				if (innerpath != cheapest_total_inner)
 				{
-					List   *newclauses;
+					/* Avoid rebuilding clause list if we already made one;
-
+					 * saves memory in big join trees...
-					newclauses = ltruncate(clausecnt,
+					 */
-										   get_actual_clauses(mergeclauses));
+					if (newclauses == NIL)
+					{
+						if (clausecnt < num_mergeclauses)
+							newclauses = ltruncate(clausecnt,
+												   listCopy(mergeclauses));
+						else
+							newclauses = mergeclauses;
+					}
 					add_path(joinrel, (Path *)
 							 create_mergejoin_path(joinrel,
 												   outerpath,
@@ -461,7 +476,7 @@ match_unsorted_inner(Query *root,
 									   innerpath,
 									   restrictlist,
 									   merge_pathkeys,
-									   get_actual_clauses(mergeclauses),
+									   mergeclauses,
 									   outersortkeys,
 									   NIL));
 		/*
@@ -487,7 +502,7 @@ match_unsorted_inner(Query *root,
 									   innerpath,
 									   restrictlist,
 									   merge_pathkeys,
-									   get_actual_clauses(mergeclauses),
+									   mergeclauses,
 									   NIL,
 									   NIL));
 
@@ -505,7 +520,7 @@ match_unsorted_inner(Query *root,
 										   innerpath,
 										   restrictlist,
 										   merge_pathkeys,
-										   get_actual_clauses(mergeclauses),
+										   mergeclauses,
 										   NIL,
 										   NIL));
 		}
@@ -552,6 +567,7 @@ hash_inner_and_outer(Query *root,
 		Var		   *left,
 				   *right,
 				   *inner;
+		List	   *hashclauses;
 		Selectivity	innerdisbursion;
 
 		if (restrictinfo->hashjoinoperator == InvalidOid)
@@ -572,6 +588,9 @@ hash_inner_and_outer(Query *root,
 		else
 			continue;			/* no good for these input relations */
 
+		/* always a one-element list of hash clauses */
+		hashclauses = lcons(restrictinfo, NIL);
+
 		/* estimate disbursion of inner var for costing purposes */
 		innerdisbursion = estimate_disbursion(root, inner);
 
@@ -585,7 +604,7 @@ hash_inner_and_outer(Query *root,
 									  outerrel->cheapest_total_path,
 									  innerrel->cheapest_total_path,
 									  restrictlist,
-									  lcons(clause, NIL),
+									  hashclauses,
 									  innerdisbursion));
 		if (outerrel->cheapest_startup_path != outerrel->cheapest_total_path)
 			add_path(joinrel, (Path *)
@@ -593,7 +612,7 @@ hash_inner_and_outer(Query *root,
 										  outerrel->cheapest_startup_path,
 										  innerrel->cheapest_total_path,
 										  restrictlist,
-										  lcons(clause, NIL),
+										  hashclauses,
 										  innerdisbursion));
 	}
 }

src/backend/optimizer/path/pathkeys.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.19 2000/02/15 20:49:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.20 2000/02/18 23:47:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -778,6 +778,7 @@ make_pathkeys_for_mergeclauses(Query *root,
 		Node	   *key;
 		Oid			sortop;
 		PathKeyItem *item;
+		List	   *pathkey;
 
 		Assert(restrictinfo->mergejoinoperator != InvalidOid);
 
@@ -791,10 +792,21 @@ make_pathkeys_for_mergeclauses(Query *root,
 		key = (Node *) get_leftop(restrictinfo->clause);
 		sortop = restrictinfo->left_sortop;
 		/*
-		 * Add a pathkey sublist for this sort item
+		 * Find pathkey sublist for this sort item.  We expect to find
+		 * the canonical set including the mergeclause's left and right
+		 * sides; if we get back just the one item, something is rotten.
 		 */
 		item = makePathKeyItem(key, sortop);
-		pathkeys = lappend(pathkeys, make_canonical_pathkey(root, item));
+		pathkey = make_canonical_pathkey(root, item);
+		Assert(length(pathkey) > 1);
+		/*
+		 * Since the item we just made is not in the returned canonical set,
+		 * we can free it --- this saves a useful amount of storage in a
+		 * big join tree.
+		 */
+		pfree(item);
+
+		pathkeys = lappend(pathkeys, pathkey);
 	}
 
 	return pathkeys;

src/backend/optimizer/plan/createplan.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.85 2000/02/15 20:49:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.86 2000/02/18 23:47:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -626,13 +626,14 @@ create_mergejoin_node(MergePath *best_path,
 			   *mergeclauses;
 	MergeJoin  *join_node;
 
+	mergeclauses = get_actual_clauses(best_path->path_mergeclauses);
+
 	/*
 	 * Remove the mergeclauses from the list of join qual clauses,
 	 * leaving the list of quals that must be checked as qpquals.
 	 * Set those clauses to contain INNER/OUTER var references.
 	 */
-	qpqual = join_references(set_difference(clauses,
+	qpqual = join_references(set_difference(clauses, mergeclauses),
-											best_path->path_mergeclauses),
 							 outer_tlist,
 							 inner_tlist,
 							 (Index) 0);
@@ -641,7 +642,7 @@ create_mergejoin_node(MergePath *best_path,
 	 * Now set the references in the mergeclauses and rearrange them so
 	 * that the outer variable is always on the left.
 	 */
-	mergeclauses = switch_outer(join_references(best_path->path_mergeclauses,
+	mergeclauses = switch_outer(join_references(mergeclauses,
 												outer_tlist,
 												inner_tlist,
 												(Index) 0));
@@ -692,14 +693,14 @@ create_hashjoin_node(HashPath *best_path,
 	 * We represent it as a list anyway, for convenience with routines
 	 * that want to work on lists of clauses.
 	 */
+	hashclauses = get_actual_clauses(best_path->path_hashclauses);
 
 	/*
 	 * Remove the hashclauses from the list of join qual clauses,
 	 * leaving the list of quals that must be checked as qpquals.
 	 * Set those clauses to contain INNER/OUTER var references.
 	 */
-	qpqual = join_references(set_difference(clauses,
+	qpqual = join_references(set_difference(clauses, hashclauses),
-											best_path->path_hashclauses),
 							 outer_tlist,
 							 inner_tlist,
 							 (Index) 0);
@@ -708,7 +709,7 @@ create_hashjoin_node(HashPath *best_path,
 	 * Now set the references in the hashclauses and rearrange them so
 	 * that the outer variable is always on the left.
 	 */
-	hashclauses = switch_outer(join_references(best_path->path_hashclauses,
+	hashclauses = switch_outer(join_references(hashclauses,
 											   outer_tlist,
 											   inner_tlist,
 											   (Index) 0));

src/backend/optimizer/util/pathnode.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.60 2000/02/15 20:49:20 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.61 2000/02/18 23:47:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -416,7 +416,8 @@ create_nestloop_path(RelOptInfo *joinrel,
  * 'inner_path' is the inner path
  * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
  * 'pathkeys' are the path keys of the new join path
- * 'mergeclauses' are the applicable join/restriction clauses
+ * 'mergeclauses' are the RestrictInfo nodes to use as merge clauses
+ *		(this should be a subset of the restrict_clauses list)
  * 'outersortkeys' are the sort varkeys for the outer relation
  * 'innersortkeys' are the sort varkeys for the inner relation
  *
@@ -473,6 +474,7 @@ create_mergejoin_path(RelOptInfo *joinrel,
  * 'inner_path' is the cheapest inner path
  * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
  * 'hashclauses' is a list of the hash join clause (always a 1-element list)
+ *		(this should be a subset of the restrict_clauses list)
  * 'innerdisbursion' is an estimate of the disbursion of the inner hash key
  *
  */

src/backend/optimizer/util/relnode.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.24 2000/02/15 20:49:21 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.25 2000/02/18 23:47:31 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -345,11 +345,8 @@ subbuild_joinrel_restrictlist(RelOptInfo *joinrel,
 	foreach(xjoininfo, joininfo_list)
 	{
 		JoinInfo   *joininfo = (JoinInfo *) lfirst(xjoininfo);
-		Relids		new_unjoined_relids;
 
-		new_unjoined_relids = set_differencei(joininfo->unjoined_relids,
+		if (is_subseti(joininfo->unjoined_relids, joinrel->relids))
-											  joinrel->relids);
-		if (new_unjoined_relids == NIL)
 		{
 			/*
 			 * Clauses in this JoinInfo list become restriction clauses

src/include/nodes/relation.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: relation.h,v 1.44 2000/02/15 20:49:25 tgl Exp $
+ * $Id: relation.h,v 1.45 2000/02/18 23:47:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -237,6 +237,8 @@ typedef struct Path
  * are usable as indexquals (as determined by indxpath.c) may appear here.
  * NOTE that the semantics of the top-level list in 'indexqual' is OR
  * combination, while the sublists are implicitly AND combinations!
+ * Also note that indexquals lists do not contain RestrictInfo nodes,
+ * just bare clause expressions.
  *
  * 'indexscandir' is one of:
  *		ForwardScanDirection: forward scan of an ordered index
@@ -293,32 +295,39 @@ typedef JoinPath NestPath;
 /*
  * A mergejoin path has these fields.
  *
+ * path_mergeclauses lists the clauses (in the form of RestrictInfos)
+ * that will be used in the merge.  (Before 7.0, this was a list of
+ * bare clause expressions, but we can save on list memory by leaving
+ * it in the form of a RestrictInfo list.)
+ *
  * Note that the mergeclauses are a subset of the parent relation's
  * restriction-clause list.  Any join clauses that are not mergejoinable
  * appear only in the parent's restrict list, and must be checked by a
  * qpqual at execution time.
+ *
+ * outersortkeys (resp. innersortkeys) is NIL if the outer path
+ * (resp. inner path) is already ordered appropriately for the
+ * mergejoin.  If it is not NIL then it is a PathKeys list describing
+ * the ordering that must be created by an explicit sort step.
  */
 
 typedef struct MergePath
 {
 	JoinPath	jpath;
-	List	   *path_mergeclauses; /* join clauses used for merge */
+	List	   *path_mergeclauses; /* join clauses to be used for merge */
-	/*
+	List	   *outersortkeys;	/* keys for explicit sort, if any */
-	 * outersortkeys (resp. innersortkeys) is NIL if the outer path
+	List	   *innersortkeys;	/* keys for explicit sort, if any */
-	 * (resp. inner path) is already ordered appropriately for the
-	 * mergejoin.  If it is not NIL then it is a PathKeys list describing
-	 * the ordering that must be created by an explicit sort step.
-	 */
-	List	   *outersortkeys;
-	List	   *innersortkeys;
 } MergePath;
 
 /*
  * A hashjoin path has these fields.
  *
  * The remarks above for mergeclauses apply for hashclauses as well.
- * However, hashjoin does not care what order its inputs appear in,
+ * (But note that path_hashclauses will always be a one-element list,
- * so we have no need for sortkeys.
+ * since we only hash on one hashable clause.)
+ *
+ * Hashjoin does not care what order its inputs appear in, so we have
+ * no need for sortkeys.
  */
 
 typedef struct HashPath