Teach planner about some cases where a restriction clause can be

propagated inside an outer join.  In particular, given
LEFT JOIN ON (A = B) WHERE A = constant, we cannot conclude that
B = constant at the top level (B might be null instead), but we
can nonetheless put a restriction B = constant into the quals for
B's relation, since no inner-side rows not meeting that condition
can contribute to the final result.  Similarly, given
FULL JOIN USING (J) WHERE J = constant, we can't directly conclude
that either input J variable = constant, but it's OK to push such
quals into each input rel.  Per recent gripe from Kim Bisgaard.
Along the way, remove 'valid_everywhere' flag from RestrictInfo,
as on closer analysis it was not being used for anything, and was
defined backwards anyway.

Author: tglsfdc

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.310 2005/06/28 05:08:56 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.311 2005/07/02 23:00:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1249,7 +1249,6 @@ _copyRestrictInfo(RestrictInfo *from)
 
 	COPY_NODE_FIELD(clause);
 	COPY_SCALAR_FIELD(is_pushed_down);
-	COPY_SCALAR_FIELD(valid_everywhere);
 	COPY_SCALAR_FIELD(can_join);
 	COPY_BITMAPSET_FIELD(clause_relids);
 	COPY_BITMAPSET_FIELD(required_relids);

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.247 2005/06/28 05:08:57 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.248 2005/07/02 23:00:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -603,7 +603,6 @@ _equalRestrictInfo(RestrictInfo *a, RestrictInfo *b)
 {
 	COMPARE_NODE_FIELD(clause);
 	COMPARE_SCALAR_FIELD(is_pushed_down);
-	COMPARE_SCALAR_FIELD(valid_everywhere);
 	COMPARE_BITMAPSET_FIELD(required_relids);
 
 	/*

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.257 2005/06/28 05:08:57 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.258 2005/07/02 23:00:39 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -1164,9 +1164,13 @@ _outPlannerInfo(StringInfo str, PlannerInfo *node)
 	WRITE_NODE_FIELD(parse);
 	WRITE_NODE_FIELD(join_rel_list);
 	WRITE_NODE_FIELD(equi_key_list);
+	WRITE_NODE_FIELD(left_join_clauses);
+	WRITE_NODE_FIELD(right_join_clauses);
+	WRITE_NODE_FIELD(full_join_clauses);
 	WRITE_NODE_FIELD(in_info_list);
 	WRITE_NODE_FIELD(query_pathkeys);
 	WRITE_BOOL_FIELD(hasJoinRTEs);
+	WRITE_BOOL_FIELD(hasOuterJoins);
 	WRITE_BOOL_FIELD(hasHavingQual);
 }
 
@@ -1234,7 +1238,6 @@ _outRestrictInfo(StringInfo str, RestrictInfo *node)
 	/* NB: this isn't a complete set of fields */
 	WRITE_NODE_FIELD(clause);
 	WRITE_BOOL_FIELD(is_pushed_down);
-	WRITE_BOOL_FIELD(valid_everywhere);
 	WRITE_BOOL_FIELD(can_join);
 	WRITE_BITMAPSET_FIELD(clause_relids);
 	WRITE_BITMAPSET_FIELD(required_relids);

src/backend/optimizer/path/indxpath.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.185 2005/06/14 04:04:30 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.186 2005/07/02 23:00:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1882,7 +1882,7 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
 				{
 					resultquals = lappend(resultquals,
 										  make_restrictinfo(boolqual,
-															true, true,
+															true,
 															NULL));
 					continue;
 				}
@@ -2132,7 +2132,7 @@ prefix_quals(Node *leftop, Oid opclass,
 			elog(ERROR, "no = operator for opclass %u", opclass);
 		expr = make_opclause(oproid, BOOLOID, false,
 							 (Expr *) leftop, (Expr *) prefix_const);
-		result = list_make1(make_restrictinfo(expr, true, true, NULL));
+		result = list_make1(make_restrictinfo(expr, true, NULL));
 		return result;
 	}
 
@@ -2147,7 +2147,7 @@ prefix_quals(Node *leftop, Oid opclass,
 		elog(ERROR, "no >= operator for opclass %u", opclass);
 	expr = make_opclause(oproid, BOOLOID, false,
 						 (Expr *) leftop, (Expr *) prefix_const);
-	result = list_make1(make_restrictinfo(expr, true, true, NULL));
+	result = list_make1(make_restrictinfo(expr, true, NULL));
 
 	/*-------
 	 * If we can create a string larger than the prefix, we can say
@@ -2163,7 +2163,7 @@ prefix_quals(Node *leftop, Oid opclass,
 			elog(ERROR, "no < operator for opclass %u", opclass);
 		expr = make_opclause(oproid, BOOLOID, false,
 							 (Expr *) leftop, (Expr *) greaterstr);
-		result = lappend(result, make_restrictinfo(expr, true, true, NULL));
+		result = lappend(result, make_restrictinfo(expr, true, NULL));
 	}
 
 	return result;
@@ -2234,7 +2234,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
 						 (Expr *) leftop,
 						 (Expr *) makeConst(datatype, -1, opr1right,
 											false, false));
-	result = list_make1(make_restrictinfo(expr, true, true, NULL));
+	result = list_make1(make_restrictinfo(expr, true, NULL));
 
 	/* create clause "key <= network_scan_last( rightop )" */
 
@@ -2249,7 +2249,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
 						 (Expr *) leftop,
 						 (Expr *) makeConst(datatype, -1, opr2right,
 											false, false));
-	result = lappend(result, make_restrictinfo(expr, true, true, NULL));
+	result = lappend(result, make_restrictinfo(expr, true, NULL));
 
 	return result;
 }

src/backend/optimizer/path/orindxpath.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.72 2005/06/09 04:18:59 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.73 2005/07/02 23:00:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -90,16 +90,13 @@ create_or_index_quals(PlannerInfo *root, RelOptInfo *rel)
 	ListCell   *i;
 
 	/*
-	 * Find potentially interesting OR joinclauses.  We must ignore any
-	 * joinclauses that are not marked valid_everywhere, because they
-	 * cannot be pushed down due to outer-join rules.
+	 * Find potentially interesting OR joinclauses.
 	 */
 	foreach(i, rel->joininfo)
 	{
 		RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
 
-		if (restriction_is_or_clause(rinfo) &&
-			rinfo->valid_everywhere)
+		if (restriction_is_or_clause(rinfo))
 		{
 			/*
 			 * Use the generate_bitmap_or_paths() machinery to estimate
@@ -140,8 +137,7 @@ create_or_index_quals(PlannerInfo *root, RelOptInfo *rel)
 	 * Convert the path's indexclauses structure to a RestrictInfo tree,
 	 * and add it to the rel's restriction list.
 	 */
-	newrinfos = make_restrictinfo_from_bitmapqual((Path *) bestpath,
-												  true, true);
+	newrinfos = make_restrictinfo_from_bitmapqual((Path *) bestpath, true);
 	Assert(list_length(newrinfos) == 1);
 	or_rinfo = (RestrictInfo *) linitial(newrinfos);
 	Assert(IsA(or_rinfo, RestrictInfo));