Today, I'd like to introduce a brand-new tool, pgstatview.
- pgstatview (pre-alpha)
http://www2.uptimeforce.com/pgstatview/
pgstatview allows DBA to visualize database activities with using several metrics both inside and outside PostgreSQL: transaction commit/rollbacks, tuple inserts/updates/deletes, cache hit ratio, bgwriter writes, WAL writes, and so on. You can see some sample reports here: Sample 1, Sample 2.
pgstatview has its unique advantages.