Mark vacuum_defer_cleanup_age as PGC_POSTMASTER.

Following bug analysis of #7819 by Tom Lane

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index c1a90d1fba90467fdc5883be12b9c8e60ada997d..59a48cf3f0a4b3e5a661c22aa82053e9d602ec72 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1998,8 +1998,7 @@ SET ENABLE_SEQSCAN TO OFF;
         is measured in terms of number of write transactions occurring on the
         primary server, it is difficult to predict just how much additional
         grace time will be made available to standby queries.
-        This parameter can only be set in the <filename>postgresql.conf</>
-        file or on the server command line.
+        This parameter can only be set at server start.
        </para>
       </listitem>
      </varlistentry>

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 2483587fa3f8bbc34bd7a00008d4e7a412935ed7..92ea02a5071c3a7119918c53f56ba4942b085c45 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1631,7 +1631,12 @@ static struct config_int ConfigureNamesInt[] =
        },
 
        {
-               {"vacuum_defer_cleanup_age", PGC_SIGHUP, WAL_REPLICATION,
+               /*
+                * Setting this to a higher value without restarting postmaster
+                * can cause various bugs in TOAST object removal, CLUSTER and
+                * possibly other places, so this must be changed only on restart.
+                */
+               {"vacuum_defer_cleanup_age", PGC_POSTMASTER, WAL_REPLICATION,
                        gettext_noop("Number of transactions by which VACUUM and HOT cleanup should be deferred, if any."),
                        NULL
                },