index d6c739d96b336db28ced9bd37f25a462db8a4844..a5f520057e3021b06f2997ba61312785e5a55b8a 100644 (file)
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.249 2010年02月03日 17:25:05 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.250 2010年02月05日 23:37:43 momjian Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
@@ -1739,7 +1739,11 @@ archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"' # Windows
server to switch to a new WAL segment file periodically. When this
parameter is greater than zero, the server will switch to a new
segment file whenever this many seconds have elapsed since the last
- segment file switch. Note that archived files that are closed early
+ segment file switch, and there has been any database activity,
+ including a single checkpoint. (Increasing
+ <varname>checkpoint_timeout</> will reduce unnecessary
+ checkpoints on an idle system.)
+ Note that archived files that are closed early
due to a forced switch are still the same length as completely full
files. Therefore, it is unwise to use a very short
<varname>archive_timeout</> — it will bloat your archive
index b51cceea74d128e1536bed17f023a6766a88d288..9a3956a50944f766074ce4a154cb266107eaed98 100644 (file)
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.66 2010年01月15日 09:19:02 heikki Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.67 2010年02月05日 23:37:43 momjian Exp $
*
*-------------------------------------------------------------------------
*/
/*
* CheckArchiveTimeout -- check for archive_timeout and switch xlog files
- * if needed
+ *
+ * This will switch to a new WAL file and force an archive file write
+ * if any activity is recorded in the current WAL file, including just
+ * a single checkpoint record.
*/
static void
CheckArchiveTimeout(void)