Before you can run postgresql you'll need to create the
database files in /var/lib/pgsql. The following should do
the trick.
	# su postgres -c "initdb -D /var/lib/pgsql/data"

Additionally, a logrotation script and init script are included.
For production level log file handling please read
http://www.postgresql.org/docs/8.4/interactive/logfile-maintenance.html

In order to start postgresql at boot and stop it properly at shutdown, 
make sure rc.postgresql is executable and add the following lines to 
the following files:

	/etc/rc.d/rc.local
	==================
	# Startup postgresql
	if [ -x /etc/rc.d/rc.postgresql ]; then
		/etc/rc.d/rc.postgresql start
	fi

	/etc/rc.d/rc.local_shutdown
	===========================
	# Stop postgres
	if [ -x /etc/rc.d/rc.postgresql ]; then
		/etc/rc.d/rc.postgresql stop
	fi

Additionally, rc.postgresql script has additionalg modes for stop/restart:
  force-stop|force-restart (i.e. pg_ctl 'fast' mode)
  unclean-stop|unclean-restart (i.e. pg_ctl 'immediate' mode)
See http://www.postgresql.org/docs/8.4/static/app-pg-ctl.html

This script builds postgresql with some useful extension modules from
the contrib directory, see PG_EXTENSIONS in SlackBuild file.

Please note that in order to actually use extension, you must execute
accompanying SQL scripts located in /usr/share/postgresql/contrib