From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 14 Jun 2007 13:54:40 +0000 (+0000)
Subject: Avoid having autovacuum run multiple ANALYZE commands in a single transaction,
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=4440954f869d483bddd0a57f904b33c6be870d3e;p=users%2Fbernd%2Fpostgres.git

Avoid having autovacuum run multiple ANALYZE commands in a single transaction,
to prevent possible deadlock problems.  Per request from Tom Lane.
---

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index b38850a65b..653dbb36f6 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -389,14 +389,17 @@ vacuum(VacuumStmt *vacstmt, List *relids)
 	 * For ANALYZE (no VACUUM): if inside a transaction block, we cannot
 	 * start/commit our own transactions.  Also, there's no need to do so if
 	 * only processing one relation.  For multiple relations when not within a
-	 * transaction block, use own transactions so we can release locks sooner.
+	 * transaction block, and also in an autovacuum worker, use own
+	 * transactions so we can release locks sooner.
 	 */
 	if (vacstmt->vacuum)
 		use_own_xacts = true;
 	else
 	{
 		Assert(vacstmt->analyze);
-		if (in_outer_xact)
+		if (IsAutoVacuumProcess())
+			use_own_xacts = true;
+		else if (in_outer_xact)
 			use_own_xacts = false;
 		else if (list_length(relations) > 1)
 			use_own_xacts = true;