Fix possible failure to send final transaction counts to stats collector.

tglsfdc · tglsfdc · commit 1618b87eb172 · 2013-02-07T14:44:20.000-05:00
Normally, we suppress sending a tabstats message to the collector unless there were some actual table stats to send. However, during backend exit we should force out the message if there are any transaction commit/abort counts to send, else the session's last few commit/abort counts will never get reported at all. We had logic for this, but the short-circuit test at the top of pgstat_report_stat() ignored the "force" flag, with the consequence that session-ending transactions that touched no database-local tables would not get counted. Seems to be an oversight in my commit 641912b, which added the "force" flag. That was back in 8.3, so back-patch to all supported versions.
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
@@ -680,8 +680,8 @@ pgstat_report_stat(bool force)
 	int			i;
 
 	/* Don't expend a clock check if nothing to do */
-	if ((pgStatTabList == NULL || pgStatTabList->tsa_used == 0)
-		&& !have_function_stats)
+	if ((pgStatTabList == NULL || pgStatTabList->tsa_used == 0) &&
+		!have_function_stats && !force)
 		return;
 
 	/*
