I recently ran across a white paper entitled [http://virtuas.com/osl-osrdb-01.pdf “Open Source Relational Databases and the Enterprise”] (PDF). It provides a pretty fair look at the state of current open source databases (PostgreSQL, my$ql, Ingres, and Firebird), talks about the histroy and support options, and stackes them up to recent commercial releases (DB2 8.2, Oracle 10g, M$SQL2005). Of course one could take issue that it uses my$ql5 as a base (which is still alpha/beta/something), but it also points out how my$ql’s mindshare lead has primarily been driven through marketing, so I think on the whole it is as balanced for all the releases as you can normally hope for. One thing that did jump out at me was just how much the PostgreSQL support model differs from these other systems; they all have there single point of
failure support company, while PostgreSQL is actually slotted with 6 different companies within the report. Actually the [http://virtuas.com/ Virtuas] folks have a number of different papers on open source, once your done checking out the database one, swing by thier sight and check some out.