Further work on making use of new statistics in planner. Adjust APIs

of costsize.c routines to pass Query root, so that costsize can figure
more things out by itself and not be so dependent on its callers to tell
it everything it needs to know.  Use selectivity of hash or merge clause
to estimate number of tuples processed internally in these joins
(this is more useful than it would've been before, since eqjoinsel is
somewhat more accurate than before).

Author: tglsfdc

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.142 2001/05/20 20:28:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.143 2001/06/05 05:26:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1361,9 +1361,10 @@ _copyRestrictInfo(RestrictInfo *from)
 	 * copy remainder of node
 	 */
 	Node_Copy(from, newnode, clause);
-	newnode->eval_cost = from->eval_cost;
 	newnode->ispusheddown = from->ispusheddown;
 	Node_Copy(from, newnode, subclauseindices);
+	newnode->eval_cost = from->eval_cost;
+	newnode->this_selec = from->this_selec;
 	newnode->mergejoinoperator = from->mergejoinoperator;
 	newnode->left_sortop = from->left_sortop;
 	newnode->right_sortop = from->right_sortop;

src/backend/nodes/equalfuncs.c

@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.90 2001/05/20 20:28:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.91 2001/06/05 05:26:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -514,14 +514,14 @@ _equalRestrictInfo(RestrictInfo *a, RestrictInfo *b)
 {
 	if (!equal(a->clause, b->clause))
 		return false;
-
-	/*
-	 * ignore eval_cost, left/right_pathkey, and left/right_bucketsize,
-	 * since they may not be set yet, and should be derivable from the
-	 * clause anyway
-	 */
 	if (a->ispusheddown != b->ispusheddown)
 		return false;
+	/*
+	 * We ignore eval_cost, this_selec, left/right_pathkey, and
+	 * left/right_bucketsize, since they may not be set yet, and should be
+	 * derivable from the clause anyway.  Probably it's not really necessary
+	 * to compare any of these remaining fields ...
+	 */
 	if (!equal(a->subclauseindices, b->subclauseindices))
 		return false;
 	if (a->mergejoinoperator != b->mergejoinoperator)

src/backend/nodes/readfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.109 2001/05/20 20:28:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.110 2001/06/05 05:26:04 tgl Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -1792,6 +1792,8 @@ _readRestrictInfo(void)
 
 	/* eval_cost is not part of saved representation; compute on first use */
 	local_node->eval_cost = -1;
+	/* ditto for this_selec */
+	local_node->this_selec = -1;
 	/* ditto for cached pathkeys and bucketsize */
 	local_node->left_pathkey = NIL;
 	local_node->right_pathkey = NIL;

src/backend/optimizer/path/allpaths.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.74 2001/05/20 20:28:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.75 2001/06/05 05:26:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -223,7 +223,7 @@ set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte)
 	 */
 
 	/* Consider sequential scan */
-	add_path(rel, create_seqscan_path(rel));
+	add_path(rel, create_seqscan_path(root, rel));
 
 	/* Consider TID scans */
 	create_tidscan_paths(root, rel);

src/backend/optimizer/path/clausesel.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/clausesel.c,v 1.44 2001/05/20 20:28:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/clausesel.c,v 1.45 2001/06/05 05:26:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -48,9 +48,6 @@ typedef struct RangeQueryClause
 
 static void addRangeClause(RangeQueryClause **rqlist, Node *clause,
 						   bool varonleft, bool isLTsel, Selectivity s2);
-static Selectivity clause_selectivity(Query *root,
-				   Node *clause,
-				   int varRelid);
 
 
 /****************************************************************************
@@ -364,7 +361,7 @@ addRangeClause(RangeQueryClause **rqlist, Node *clause,
  * When varRelid is 0, all variables are treated as variables.	This
  * is appropriate for ordinary join clauses and restriction clauses.
  */
-static Selectivity
+Selectivity
 clause_selectivity(Query *root,
 				   Node *clause,
 				   int varRelid)