1 files changed, 51 insertions, 2 deletions

diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 5658f24323f..91885084cdd 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -20,6 +20,7 @@
 #include <math.h>
 
 #include "access/sysattr.h"
+#include "catalog/pg_am.h"
 #include "catalog/pg_class.h"
 #include "foreign/fdwapi.h"
 #include "miscadmin.h"
@@ -191,6 +192,7 @@ static IndexOnlyScan *make_indexonlyscan(List *qptlist, List *qpqual,
 										 List *indexqual, List *indexorderby,
 										 List *indextlist,
 										 ScanDirection indexscandir);
+static List *make_indexonly_tlist(IndexOptInfo *indexinfo);
 static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
 											  List *indexqual,
 											  List *indexqualorig);
@@ -621,7 +623,7 @@ create_scan_plan(PlannerInfo *root, Path *best_path, int flags)
 		if (best_path->pathtype == T_IndexOnlyScan)
 		{
 			/* For index-only scan, the preferred tlist is the index's */
-			tlist = copyObject(((IndexPath *) best_path)->indexinfo->indextlist);
+			tlist = copyObject(make_indexonly_tlist(((IndexPath *) best_path)->indexinfo));
 
 			/*
 			 * Transfer sortgroupref data to the replacement tlist, if
@@ -3070,7 +3072,7 @@ create_indexscan_plan(PlannerInfo *root,
 												indexoid,
 												fixed_indexquals,
 												fixed_indexorderbys,
-												best_path->indexinfo->indextlist,
+												make_indexonly_tlist(best_path->indexinfo),
 												best_path->indexscandir);
 	else
 		scan_plan = (Scan *) make_indexscan(tlist,
@@ -5462,6 +5464,53 @@ make_indexonlyscan(List *qptlist,
 	return node;
 }
 
+/*
+ * make_indexonly_tlist
+ *
+ * Construct the indextlist for an IndexOnlyScan plan node.
+ * We must replace any column that can't be returned by the index AM
+ * with a null Const of the appropriate datatype.  This is necessary
+ * to prevent setrefs.c from trying to use the value of such a column,
+ * and anyway it makes the indextlist a better representative of what
+ * the indexscan will really return.  (We do this here, not where the
+ * IndexOptInfo is originally constructed, because earlier planner
+ * steps need to know what is in such columns.)
+ */
+static List *
+make_indexonly_tlist(IndexOptInfo *indexinfo)
+{
+	List	   *result;
+	int			i;
+	ListCell   *lc;
+
+	/* We needn't work hard for the common case of btrees. */
+	if (indexinfo->relam == BTREE_AM_OID)
+		return indexinfo->indextlist;
+
+	result = NIL;
+	i = 0;
+	foreach(lc, indexinfo->indextlist)
+	{
+		TargetEntry *indextle = (TargetEntry *) lfirst(lc);
+
+		if (indexinfo->canreturn[i])
+			result = lappend(result, indextle);
+		else
+		{
+			TargetEntry *newtle = makeNode(TargetEntry);
+			Node	   *texpr = (Node *) indextle->expr;
+
+			memcpy(newtle, indextle, sizeof(TargetEntry));
+			newtle->expr = (Expr *) makeNullConst(exprType(texpr),
+												  exprTypmod(texpr),
+												  exprCollation(texpr));
+			result = lappend(result, newtle);
+		}
+		i++;
+	}
+	return result;
+}
+
 static BitmapIndexScan *
 make_bitmap_indexscan(Index scanrelid,
 					  Oid indexid,