From e9c8b6013ee4e5547338f05ad62227f17c402cfe Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Wed, 3 Jun 2009 00:38:34 +0000
Subject: [PATCH] Add example of how to generate the session identifier from
 pg_stat_activity.

---
 doc/src/sgml/config.sgml | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index b2e3ad3f97..b30e8e2e66 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3088,7 +3088,14 @@ local0.*    /var/log/postgresql
          consisting of two 4-byte hexadecimal numbers (without leading zeros)
          separated by a dot.  The numbers are the process start time and the
          process ID, so <literal>%c</> can also be used as a space saving way
-         of printing those items.
+         of printing those items.  For example, to generate the session
+         identifier from <literal>pg_stat_activity</>, use:
+<programlisting>
+SELECT to_hex(EXTRACT(EPOCH FROM backend_start)::integer) || '.' ||
+       to_hex(procpid)
+FROM pg_stat_activity;
+</programlisting>
+
        </para>
 
        <tip>
-- 
2.30.2