Flush any remaining statistics counts out to the collector at process

exit.  Without this, operations triggered during backend exit (such as
temp table deletions) won't be counted ... which given heavy usage of
temp tables can lead to pg_autovacuum falling way behind on the need
to vacuum pg_class and pg_attribute.  Per reports from Steve Crawford
and others.

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 115feaaf2830f996e2a3cb77ed01c38366991e57..551d91f7490c3debf4b3dd42ba9f17bf3284cea8 100644 (file)
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -13,7 +13,7 @@
  *
  *     Copyright (c) 2001-2003, PostgreSQL Global Development Group
  *
- *     $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.45.2.2 2003/11/15 17:24:19 tgl Exp $
+ *     $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.45.2.3 2005/03/31 23:21:32 tgl Exp $
  * ----------
  */
 #include "postgres.h"
@@ -109,6 +109,7 @@ static char pgStat_fname[MAXPGPATH];
 static void pgstat_main(void);
 static void pgstat_recvbuffer(void);
 static void pgstat_die(SIGNAL_ARGS);
+static void pgstat_beshutdown_hook(int code, Datum arg);
 
 static int     pgstat_add_backend(PgStat_MsgHdr *msg);
 static void pgstat_sub_backend(int procpid);
@@ -522,6 +523,25 @@ pgstat_bestart(void)
 
        pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_BESTART);
        pgstat_send(&msg, sizeof(msg));
+
+       /*
+        * Set up a process-exit hook to ensure we flush the last batch of
+        * statistics to the collector.
+        */
+       on_proc_exit(pgstat_beshutdown_hook, 0);
+}
+
+/*
+ * Flush any remaining statistics counts out to the collector at process
+ * exit.   Without this, operations triggered during backend exit (such as
+ * temp table deletions) won't be counted.  This is an on_proc_exit hook,
+ * not on_shmem_exit, so that everything interesting must have happened
+ * already.
+ */
+static void
+pgstat_beshutdown_hook(int code, Datum arg)
+{
+       pgstat_report_tabstat();
 }