Log Message:
-----------
Add example of how to generate the session identifier from pg_stat_activity.
Modified Files:
--------------
pgsql/doc/src/sgml:
config.sgml (r1.217 -> r1.218)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml?r1=1.217&r2=1.218)