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 a1f9cb117bc958148f21cbea009c9ff9bf2ac4bc..20a880ec9c45a38aa92c24d2e6e9cc75209c1cc5 100644 (file)
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -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;