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 cf4c34141299b68e63a3be992325896a2e6cfa7d..8fa17ab2350542472c8f39e8b28348a5465bffb2 100644 (file)
--- 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 1.352 2007/05/30 20:11:57 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.353 2007/06/14 13:53:14 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -359,14 +359,17 @@ 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 (IsAutoVacuumWorkerProcess())
+           use_own_xacts = true;
+       else if (in_outer_xact)
            use_own_xacts = false;
        else if (list_length(relations) > 1)
            use_own_xacts = true;