In pg_upgrade, set synchronous_commit=off for the new cluster, to

improve performance when restoring the schema from the old cluster.

Backpatch to 9.2.

diff --git a/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
index a9f9d85b787110aafc771a1e0cb29131037ddb17..49d4c8f9d739791fb0d9bdbe2ee35dec7dc3ec5b 100644 (file)
--- a/contrib/pg_upgrade/server.c
+++ b/contrib/pg_upgrade/server.c
@@ -208,13 +208,18 @@ start_postmaster(ClusterInfo *cluster)
         * maximum.  We assume all datfrozenxid and relfrozen values are less than
         * a gap of 2000000000 from the current xid counter, so autovacuum will
         * not touch them.
+        *
+        *      synchronous_commit=off improves object creation speed, and we only
+        *      modify the new cluster, so only use it there.  If there is a crash,
+        *      the new cluster has to be recreated anyway.
         */
        snprintf(cmd, sizeof(cmd),
-                        "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d %s %s%s\" start",
+                        "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d%s%s%s%s\" start",
                  cluster->bindir, SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
                         (cluster->controldata.cat_ver >=
-                         BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
-                        "-c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
+                         BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? " -b" :
+                        " -c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
+                        (cluster == &new_cluster) ? " -c synchronous_commit=off" : "",
                         cluster->pgopts ? cluster->pgopts : "", socket_string);
 
        /*