Minor improvements to the description of archive_timeout.

doc/src/sgml/config.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.94 2006/11/05 22:42:07 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.95 2006/11/12 05:12:42 neilc Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -1601,24 +1601,22 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"'  # Windows
       </indexterm>
       <listitem>
        <para>
-        The <xref linkend="guc-archive-command"> is only invoked on completed 
+        The <xref linkend="guc-archive-command"> is only invoked on
-        WAL segments. Hence,
+        completed WAL segments. Hence, if your server generates little WAL
-        if your server generates only little WAL traffic (or has slack periods 
+        traffic (or has slack periods where it does so), there could be a
-        where it does so), there could be a long delay between the completion
+        long delay between the completion of a transaction and its safe
-        of a transaction and its safe recording in archive storage.  To put
+        recording in archive storage.  To put a limit on how old unarchived
-        a limit on how old unarchived data can be, you can set
+        data can be, you can set <varname>archive_timeout</> to force the
-        <varname>archive_timeout</> to force the server to switch
+        server to switch to a new WAL segment file periodically.  When this
-        to a new WAL segment file periodically.  When this parameter is
+        parameter is greater than zero, the server will switch to a new
-        greater than zero, the server will switch to a new segment file
+        segment file whenever this many seconds have elapsed since the last
-        whenever this many seconds elapse since the last segment file switch.
+        segment file switch.  Note that archived files that are closed early
-        Note that archived
+        due to a forced switch are still the same length as completely full
-        files that are closed early due to a forced switch are still the same
+        files.  Therefore, it is unwise to use a very short
-        length as completely full files.  It is therefore unwise to set a very
+        <varname>archive_timeout</> &mdash; it will bloat your archive
-        short <varname>archive_timeout</> &mdash; it will bloat your archive
         storage.  <varname>archive_timeout</> settings of a minute or so are
-        usually reasonable.
+        usually reasonable.  This parameter can only be set in the
-        This parameter can only be set in the <filename>postgresql.conf</>
+        <filename>postgresql.conf</> file or on the server command line.
-        file or on the server command line.
        </para>
       </listitem>
      </varlistentry>