We no longer need a snapshot set after opening the finishing transaction: this

alvherre · alvherre · commit a9686591d7fa · 2008-03-19T14:18:21.000Z
is redundant because autovacuum now always analyzes a single table per
transaction.
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.367 2008/03/14 17:25:58 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.368 2008/03/19 14:18:21 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -482,15 +482,6 @@ vacuum(VacuumStmt *vacstmt, List *relids,
 		 * PostgresMain().
 		 */
 		StartTransactionCommand();
-
-		/*
-		 * Re-establish the transaction snapshot.  This is wasted effort when
-		 * we are called as a normal utility command, because the new
-		 * transaction will be dropped immediately by PostgresMain(); but it's
-		 * necessary if we are called from autovacuum because autovacuum might
-		 * continue on to do an ANALYZE-only call.
-		 */
-		ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
 	}
 
 	if (vacstmt->vacuum && !IsAutoVacuumWorkerProcess())

Original file line number	Diff line number	Diff line change
`@@ -13,7 +13,7 @@`
`13`	`13`	`*`
`14`	`14`	`*`
`15`	`15`	`* IDENTIFICATION`
`16`		`- * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.367 2008/03/14 17:25:58 alvherre Exp $`
	`16`	`+ * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.368 2008/03/19 14:18:21 alvherre Exp $`
`17`	`17`	`*`
`18`	`18`	`*-------------------------------------------------------------------------`
`19`	`19`	`*/`
`@@ -482,15 +482,6 @@ vacuum(VacuumStmt vacstmt, List relids,`
`482`	`482`	`* PostgresMain().`
`483`	`483`	`*/`
`484`	`484`	`StartTransactionCommand();`
`485`		`-`
`486`		`- /*`
`487`		`- * Re-establish the transaction snapshot. This is wasted effort when`
`488`		`- * we are called as a normal utility command, because the new`
`489`		`- * transaction will be dropped immediately by PostgresMain(); but it's`
`490`		`- * necessary if we are called from autovacuum because autovacuum might`
`491`		`- * continue on to do an ANALYZE-only call.`
`492`		`- */`
`493`		`- ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());`
`494`	`485`	`}`
`495`	`486`
`496`	`487`	`if (vacstmt->vacuum && !IsAutoVacuumWorkerProcess())`