Implement SQL-compliant treatment of row comparisons for < <= > >= cases

(previously we only did = and <> correctly).  Also, allow row comparisons
with any operators that are in btree opclasses, not only those with these
specific names.  This gets rid of a whole lot of indefensible assumptions
about the behavior of particular operators based on their names ... though
it's still true that IN and NOT IN expand to "= ANY".  The patch adds a
RowCompareExpr expression node type, and makes some changes in the
representation of ANY/ALL/ROWCOMPARE SubLinks so that they can share code
with RowCompareExpr.

I have not yet done anything about making RowCompareExpr an indexable
operator, but will look at that soon.

initdb forced due to changes in stored rules.

1 files changed, 18 insertions, 6 deletions

diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index aa5fd99db8..b60eab31fd 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.265 2005/12/20 02:30:35 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.266 2005/12/28 01:29:59 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -736,10 +736,8 @@ _outSubLink(StringInfo str, SubLink *node)
 	WRITE_NODE_TYPE("SUBLINK");
 
 	WRITE_ENUM_FIELD(subLinkType, SubLinkType);
-	WRITE_BOOL_FIELD(useOr);
-	WRITE_NODE_FIELD(lefthand);
+	WRITE_NODE_FIELD(testexpr);
 	WRITE_NODE_FIELD(operName);
-	WRITE_NODE_FIELD(operOids);
 	WRITE_NODE_FIELD(subselect);
 }
 
@@ -749,8 +747,7 @@ _outSubPlan(StringInfo str, SubPlan *node)
 	WRITE_NODE_TYPE("SUBPLAN");
 
 	WRITE_ENUM_FIELD(subLinkType, SubLinkType);
-	WRITE_BOOL_FIELD(useOr);
-	WRITE_NODE_FIELD(exprs);
+	WRITE_NODE_FIELD(testexpr);
 	WRITE_NODE_FIELD(paramIds);
 	WRITE_NODE_FIELD(plan);
 	WRITE_INT_FIELD(plan_id);
@@ -856,6 +853,18 @@ _outRowExpr(StringInfo str, RowExpr *node)
 }
 
 static void
+_outRowCompareExpr(StringInfo str, RowCompareExpr *node)
+{
+	WRITE_NODE_TYPE("ROWCOMPARE");
+
+	WRITE_ENUM_FIELD(rctype, RowCompareType);
+	WRITE_NODE_FIELD(opnos);
+	WRITE_NODE_FIELD(opclasses);
+	WRITE_NODE_FIELD(largs);
+	WRITE_NODE_FIELD(rargs);
+}
+
+static void
 _outCoalesceExpr(StringInfo str, CoalesceExpr *node)
 {
 	WRITE_NODE_TYPE("COALESCE");
@@ -1936,6 +1945,9 @@ _outNode(StringInfo str, void *obj)
 			case T_RowExpr:
 				_outRowExpr(str, obj);
 				break;
+			case T_RowCompareExpr:
+				_outRowCompareExpr(str, obj);
+				break;
 			case T_CoalesceExpr:
 				_outCoalesceExpr(str, obj);
 				break;