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.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index be684094119..07b67a88228 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/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;
 }