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, 13 insertions, 1 deletions

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 11b0bc0eb3f..15c6085569c 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.157 2005/11/22 18:17:33 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.158 2005/12/28 01:30:01 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -4283,6 +4283,18 @@ exec_simple_check_node(Node *node)
 				return TRUE;
 			}
 
+		case T_RowCompareExpr:
+			{
+				RowCompareExpr    *expr = (RowCompareExpr *) node;
+
+				if (!exec_simple_check_node((Node *) expr->largs))
+					return FALSE;
+				if (!exec_simple_check_node((Node *) expr->rargs))
+					return FALSE;
+
+				return TRUE;
+			}
+
 		case T_CoalesceExpr:
 			{
 				CoalesceExpr *expr = (CoalesceExpr *) node;