diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 393cdf691de..f3764344f1d 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 1.191.2.4 2005/12/06 16:50:46 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.191.2.5 2006/01/29 17:27:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -326,7 +326,8 @@ find_usable_indexes(PlannerInfo *root, RelOptInfo *rel,
 		if (istoplevel && index_is_ordered && !isjoininner)
 		{
 			index_pathkeys = build_index_pathkeys(root, index,
-												  ForwardScanDirection);
+												  ForwardScanDirection,
+												  true);
 			useful_pathkeys = truncate_useless_pathkeys(root, rel,
 														index_pathkeys);
 		}
@@ -1512,7 +1513,7 @@ match_index_to_query_keys(PlannerInfo *root,
 	ListCell   *r;
 
 	/* Get the pathkeys that exactly describe the index */
-	index_pathkeys = build_index_pathkeys(root, index, indexscandir);
+	index_pathkeys = build_index_pathkeys(root, index, indexscandir, false);
 
 	/*
 	 * Can we match to the query's requested pathkeys?  The inner loop skips
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 04d0914f036..f6ea5eb7fa9 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.73.2.1 2005/11/22 18:23:10 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.73.2.2 2006/01/29 17:27:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -909,13 +909,20 @@ get_cheapest_fractional_path_for_pathkeys(List *paths,
  * If 'scandir' is BackwardScanDirection, attempt to build pathkeys
  * representing a backwards scan of the index.	Return NIL if can't do it.
  *
+ * If 'canonical' is TRUE, we remove duplicate pathkeys (which can occur
+ * if two index columns are equijoined, eg WHERE x = 1 AND y = 1).  This
+ * is required if the result is to be compared directly to a canonical query
+ * pathkeys list.  However, some callers want a list with exactly one entry
+ * per index column, and they must pass FALSE.
+ *
  * We generate the full pathkeys list whether or not all are useful for the
  * current query.  Caller should do truncate_useless_pathkeys().
  */
 List *
 build_index_pathkeys(PlannerInfo *root,
 					 IndexOptInfo *index,
-					 ScanDirection scandir)
+					 ScanDirection scandir,
+					 bool canonical)
 {
 	List	   *retval = NIL;
 	int		   *indexkeys = index->indexkeys;
@@ -956,11 +963,11 @@ build_index_pathkeys(PlannerInfo *root,
 		item = makePathKeyItem(indexkey, sortop, true);
 		cpathkey = make_canonical_pathkey(root, item);
 
-		/*
-		 * Eliminate redundant ordering info; could happen if query is such
-		 * that index keys are equijoined...
-		 */
-		retval = list_append_unique_ptr(retval, cpathkey);
+		/* Eliminate redundant ordering info if requested */
+		if (canonical)
+			retval = list_append_unique_ptr(retval, cpathkey);
+		else
+			retval = lappend(retval, cpathkey);
 
 		indexkeys++;
 		ordering++;
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 4020f4bf49a..d71fba25497 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.88 2005/10/15 02:49:45 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.88.2.1 2006/01/29 17:27:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -108,7 +108,7 @@ extern Path *get_cheapest_fractional_path_for_pathkeys(List *paths,
 										  List *pathkeys,
 										  double fraction);
 extern List *build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index,
-					 ScanDirection scandir);
+					 ScanDirection scandir, bool canonical);
 extern List *convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel,
 						  List *subquery_pathkeys);
 extern List *build_join_pathkeys(PlannerInfo *root,