Revolution Systems Blog

Which PostgreSQL backend am I using?

Someone asked me how to determine which PostgreSQL backend a particular client was connected to.  Everyone's first thought is to do a ps aux | grep postgres which will show you the IP and user, but if you have different processes connecting from the same IP with the same usernames, how do you know which is which?

One way to tell would be to see which queries are being executed by which backend and match that up to your client side.  But you can quickly get confused, especially if the various connections are all executing the same SQL statements, a web application for example.

The simplest way was suggested by Jacob Kaplan-Moss, which is to use the pg_backend_pid() function like:

SELECT pg_backend_pid();

I love it when the solution is something really simple!

SCALE Talk Slides and Audio

I just noticed that the Southern California Linux Expo (SCALE) has my slides and a MP3 of the audio of the talk up on their site.  The audio isn't actually too bad, especially considering I forgot I was being taped and moved away from the microphone during the Q&A section. 

You can also find OpenOffice and PDF versions of the slides on the Revolution Systems site. Enjoy!

Real PostgreSQL Benchmark

Josh Berkus and Sun have put together the first real PostgreSQL performance benchmark.  I run into people often who are still working under dubious performance comparisons done years ago against against competition like MySQL and Oracle. Hopefully this in depth comparison will put some of these arguments to rest.

If you're just interested in the conclusions, PostgreSQL is as fast or faster than MySQL and nearly as fast as Oracle.  I know the performance improvements over the last few years have been nothing short of phenomenal, glad to see there is now a report to back up my gut feelings.