Avoid a useless tuple copy within nodeMaterial. Neil Conway

tglsfdc · tglsfdc · commit 598b97dc9b8d · 2008-03-23T00:54:04.000Z
diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.61 2008/01/01 19:45:49 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.62 2008/03/23 00:54:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -124,18 +124,17 @@ ExecMaterial(MaterialState *node)
 		}
 
 		/*
-		 * Append returned tuple to tuplestore.  NOTE: because the tuplestore
-		 * is certainly in EOF state, its read position will move forward over
-		 * the added tuple.  This is what we want.
+		 * Append a copy of the returned tuple to tuplestore.  NOTE: because
+		 * the tuplestore is certainly in EOF state, its read position will
+		 * move forward over the added tuple.  This is what we want.
 		 */
 		if (tuplestorestate)
 			tuplestore_puttupleslot(tuplestorestate, outerslot);
 
 		/*
-		 * And return a copy of the tuple.	(XXX couldn't we just return the
-		 * outerslot?)
+		 * We can just return the subplan's returned tuple, without copying.
 		 */
-		return ExecCopySlot(slot, outerslot);
+		return outerslot;
 	}
 
 	/*

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.61 2008/01/01 19:45:49 momjian Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.62 2008/03/23 00:54:04 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -124,18 +124,17 @@ ExecMaterial(MaterialState *node)`
`124`	`124`	`}`
`125`	`125`
`126`	`126`	`/*`
`127`		`- * Append returned tuple to tuplestore. NOTE: because the tuplestore`
`128`		`- * is certainly in EOF state, its read position will move forward over`
`129`		`- * the added tuple. This is what we want.`
	`127`	`+ * Append a copy of the returned tuple to tuplestore. NOTE: because`
	`128`	`+ * the tuplestore is certainly in EOF state, its read position will`
	`129`	`+ * move forward over the added tuple. This is what we want.`
`130`	`130`	`*/`
`131`	`131`	`if (tuplestorestate)`
`132`	`132`	`tuplestore_puttupleslot(tuplestorestate, outerslot);`
`133`	`133`
`134`	`134`	`/*`
`135`		`- * And return a copy of the tuple. (XXX couldn't we just return the`
`136`		`- * outerslot?)`
	`135`	`+ * We can just return the subplan's returned tuple, without copying.`
`137`	`136`	`*/`
`138`		`- return ExecCopySlot(slot, outerslot);`
	`137`	`+ return outerslot;`
`139`	`138`	`}`
`140`	`139`
`141`	`140`	`/*`