I came across the following document posted to the mysql mailing list today. It’s a great feature comparison between MySQL, PostgreSQL, Firebird, MaxDB and Ingres.
You can download the paper here.
Whilst this may only list supported features as of MySQL 4.1.10 - once you know the new features available in MySQL 5.0, it’s easy to see there really isn’t very much holding MySQL back when compared to other open source offerings.
This is certainly one of those papers that should be handed to all of those PostgreSQL “fanboys” that constantly spout about MySQL *not* supporting ACID transactions, transaction isolation, row level locking and foreign keys etc. It even shows that MySQL supports *more* transaction isolation levels than PostgreSQL.
A very interesting read for anybody currently trying to decide which open source offering to go with!

A long and thorough comparison of the Open Source databases available.

Mark Leith » Blog Archive » Open Source DB Comparisons