How to profile PostgreSQL Database?

I want to profile (keep an Eye on) all the activities that goes on in a Database which is in PostgreSQL.

Is there any such utility which will help me do this?

From stackoverflow

• Well, if you're looking at what's going on, regarding selects, updates, deletes, and so on, there are a few tables in the pg_catalog schema, I mainly use pg_stat_user_tables and pg_stat_user_indexes but there are many more, all within pg_stat*.

  There also is the pg_stat_activity view which tells you what's running on your server right now.

  I've hacked together four munin plugins that uses the user_tables and user_indexes, they're available there

• Have a look at Nagios-Plugin script or check_postgres.pl

• "Keep an eye on" and "profile" are two quite different tasks in my view.

  For profiling (not a live view on what's going on right now, but to see which queries take most time etc), check out pgFouine:

  http://pgfouine.projects.postgresql.org/

  This will let you see which queries are resource intensive, and take appropriate action: Add missing indexes, rewrite queries using other techiques etc.

• By 'Eye On' I mean that I want to know as to what is happening at every single second in the database. I have to do this because we are using a software which is running on pgSQL and at times it performs very slowly and other times is performs a very high speed.

  Want to diagnose as to what is the problem. Why does it slow down at times?

  mat : Please, edit your question, don't post answers.

• For "keeping an eye", I use pgtop, a program which deliberately mimics Unix 'top' command.

  Gunnlaugur Briem : To save someone a minute or two: I found this only under the package name ptop in Debian, though the command itself is called pg_top.

• Thanks everyone

  bortzmeyer : Edit your question, do not post answers. And read the comments, it was already said.