Change build_index_pathkeys() so that the expressions it builds to represent

index key columns always have the type expected by the index's associated
operators, ie, we add RelabelType nodes when dealing with binary-compatible
index opclasses.  This is needed to get varchar indexes to play nicely with
the new EquivalenceClass machinery, as per recent gripe from Josh Berkus that
CVS HEAD was failing to match a varchar index column to a constant restriction
in the query.

It seems likely that this change will allow removal of a lot of ugly ad-hoc
RelabelType-stripping that the planner has traditionally done while matching
expressions to other expressions, but I'll worry about that some other day.

1 files changed, 11 insertions, 8 deletions

diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index 605e7f64eed..70b3d7d43f5 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.135 2007/05/25 17:54:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.136 2007/05/31 16:57:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -171,20 +171,23 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			info->ncolumns = ncolumns = index->indnatts;
 
 			/*
-			 * Need to make opfamily array large enough to put a terminating
-			 * zero at the end.
+			 * Allocate per-column info arrays.  To save a few palloc cycles
+			 * we allocate all the Oid-type arrays in one request.  Note that
+			 * the opfamily array needs an extra, terminating zero at the end.
+			 * We pre-zero the ordering info in case the index is unordered.
 			 */
 			info->indexkeys = (int *) palloc(sizeof(int) * ncolumns);
-			info->opfamily = (Oid *) palloc0(sizeof(Oid) * (ncolumns + 1));
-			/* initialize these to zeroes in case index is unordered */
-			info->fwdsortop = (Oid *) palloc0(sizeof(Oid) * ncolumns);
-			info->revsortop = (Oid *) palloc0(sizeof(Oid) * ncolumns);
+			info->opfamily = (Oid *) palloc0(sizeof(Oid) * (4 * ncolumns + 1));
+			info->opcintype = info->opfamily + (ncolumns + 1);
+			info->fwdsortop = info->opcintype + ncolumns;
+			info->revsortop = info->fwdsortop + ncolumns;
 			info->nulls_first = (bool *) palloc0(sizeof(bool) * ncolumns);
 
 			for (i = 0; i < ncolumns; i++)
 			{
-				info->opfamily[i] = indexRelation->rd_opfamily[i];
 				info->indexkeys[i] = index->indkey.values[i];
+				info->opfamily[i] = indexRelation->rd_opfamily[i];
+				info->opcintype[i] = indexRelation->rd_opcintype[i];
 			}
 
 			info->relam = indexRelation->rd_rel->relam;