This postgresql plugin provides metrics for your postgres database. It currently works with postgres versions 8.1+. It uses data from the built in _pg_stat_database_ and pg_stat_bgwriter views. The metrics recorded depend on your version of postgres. See table:
More information about the meaning of these metrics can be found in the [PostgreSQL Documentation](http://www.postgresql.org/docs/9.2/static/monitoring-stats.html#PG-STAT-DATABASE-VIEW)