diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index 48290d14cb5a28cc92a8d013ee19efca7e48a943..2a9ccf82320062efa0d55ca6c5f8bcfd8cf9d2b6 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.133 2009/07/18 19:15:41 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.134 2009/08/23 18:26:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -238,6 +238,10 @@ ExecIndexEvalRuntimeKeys(ExprContext *econtext,
 						 IndexRuntimeKeyInfo *runtimeKeys, int numRuntimeKeys)
 {
 	int			j;
+	MemoryContext oldContext;
+
+	/* We want to keep the key values in per-tuple memory */
+	oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
 
 	for (j = 0; j < numRuntimeKeys; j++)
 	{
@@ -256,18 +260,32 @@ ExecIndexEvalRuntimeKeys(ExprContext *econtext,
 		 * econtext->ecxt_per_tuple_memory.  We assume that the outer tuple
 		 * will stay put throughout our scan.  If this is wrong, we could copy
 		 * the result into our context explicitly, but I think that's not
-		 * necessary...
+		 * necessary.
+		 *
+		 * It's also entirely possible that the result of the eval is a
+		 * toasted value.  In this case we should forcibly detoast it,
+		 * to avoid repeat detoastings each time the value is examined
+		 * by an index support function.
 		 */
-		scanvalue = ExecEvalExprSwitchContext(key_expr,
-											  econtext,
-											  &isNull,
-											  NULL);
-		scan_key->sk_argument = scanvalue;
+		scanvalue = ExecEvalExpr(key_expr,
+								 econtext,
+								 &isNull,
+								 NULL);
 		if (isNull)
+		{
+			scan_key->sk_argument = scanvalue;
 			scan_key->sk_flags |= SK_ISNULL;
+		}
 		else
+		{
+			if (runtimeKeys[j].key_toastable)
+				scanvalue = PointerGetDatum(PG_DETOAST_DATUM(scanvalue));
+			scan_key->sk_argument = scanvalue;
 			scan_key->sk_flags &= ~SK_ISNULL;
+		}
 	}
+
+	MemoryContextSwitchTo(oldContext);
 }
 
 /*
@@ -795,6 +813,8 @@ ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
 				runtime_keys[n_runtime_keys].scan_key = this_scan_key;
 				runtime_keys[n_runtime_keys].key_expr =
 					ExecInitExpr(rightop, planstate);
+				runtime_keys[n_runtime_keys].key_toastable =
+					TypeIsToastable(op_righttype);
 				n_runtime_keys++;
 				scanvalue = (Datum) 0;
 			}
@@ -843,6 +863,31 @@ ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
 
 				varattno = ((Var *) leftop)->varattno;
 
+				/*
+				 * We have to look up the operator's associated btree support
+				 * function
+				 */
+				opno = lfirst_oid(opnos_cell);
+				opnos_cell = lnext(opnos_cell);
+
+				if (index->rd_rel->relam != BTREE_AM_OID ||
+					varattno < 1 || varattno > index->rd_index->indnatts)
+					elog(ERROR, "bogus RowCompare index qualification");
+				opfamily = index->rd_opfamily[varattno - 1];
+
+				get_op_opfamily_properties(opno, opfamily,
+										   &op_strategy,
+										   &op_lefttype,
+										   &op_righttype);
+
+				if (op_strategy != rc->rctype)
+					elog(ERROR, "RowCompare index qualification contains wrong operator");
+
+				opfuncid = get_opfamily_proc(opfamily,
+											 op_lefttype,
+											 op_righttype,
+											 BTORDER_PROC);
+
 				/*
 				 * rightop is the constant or variable comparison value
 				 */
@@ -867,35 +912,12 @@ ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
 					runtime_keys[n_runtime_keys].scan_key = this_sub_key;
 					runtime_keys[n_runtime_keys].key_expr =
 						ExecInitExpr(rightop, planstate);
+					runtime_keys[n_runtime_keys].key_toastable =
+						TypeIsToastable(op_righttype);
 					n_runtime_keys++;
 					scanvalue = (Datum) 0;
 				}
 
-				/*
-				 * We have to look up the operator's associated btree support
-				 * function
-				 */
-				opno = lfirst_oid(opnos_cell);
-				opnos_cell = lnext(opnos_cell);
-
-				if (index->rd_rel->relam != BTREE_AM_OID ||
-					varattno < 1 || varattno > index->rd_index->indnatts)
-					elog(ERROR, "bogus RowCompare index qualification");
-				opfamily = index->rd_opfamily[varattno - 1];
-
-				get_op_opfamily_properties(opno, opfamily,
-										   &op_strategy,
-										   &op_lefttype,
-										   &op_righttype);
-
-				if (op_strategy != rc->rctype)
-					elog(ERROR, "RowCompare index qualification contains wrong operator");
-
-				opfuncid = get_opfamily_proc(opfamily,
-											 op_lefttype,
-											 op_righttype,
-											 BTORDER_PROC);
-
 				/*
 				 * initialize the subsidiary scan key's fields appropriately
 				 */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 1b60bda46917375ba3b4353222b4b6f499344742..742ff325752234db5e9a84590c954c1a42bd0305 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.206 2009/08/06 20:44:31 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.207 2009/08/23 18:26:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1084,6 +1084,7 @@ typedef struct
 {
 	ScanKey		scan_key;		/* scankey to put value into */
 	ExprState  *key_expr;		/* expr to evaluate to get value */
+	bool		key_toastable;	/* is expr's result a toastable datatype? */
 } IndexRuntimeKeyInfo;
 
 typedef struct