For everyone out there that's wrestling with the choice of two equals for your database backend (between MySQL and Postgres), this new DevArticle piece just might help you out...

In MySQL and PostgreSQL Compared, the infamous Tim Perdue goes into some "real page" testing with a MySQL/PHP server and a Postgres/PHP server with the same content on each page. He used the "ab" (Apache Benchmarking Tool) to give the pages a good beating - with the Postgres times usually coming out on top. The most interesting thing about my test results was to see how much of a load Postgres could withstand before giving any errors. In fact, Postgres seemed to scale 3 times higher than MySQL before giving any errors at all. MySQL begins collapsing at about 40-50 concurrent connections, whereas Postgres handily scaled to 120 before balking. My guess is that Postgres could have gone far past 120 connections with enough memory and CPU.

It's interesting to see that MySQL, the winner of the popular vote, is just a tiny bit slower at things than its cousin, Postgres. MySQL is a good, fast, lightweight database system that can handle smaller sites with no problem - but the second you start getting into more complicated things and larger sites, you might consider moving to a Postgres platform....