Interesting rant mentioning PostgreSQL...

http://blog.develix.com/frog/user/cliff/article/2006-06-04/9

I learned databases on MySQL and used it for several years. Then I
discovered PostgreSQL and realized that in fact, I'd learned nothing
of databases. For years the MySQL developers were quite vocal that
things like referential integrity, transactions, subselects, etc were
little more than baggage that could be done better another way. They
were after speed, pure and simple. Fair enough, in some respect,
since the job MySQL was originally developed for didn't require any
of those things. The problem is that a whole generation of database
programmers believed them, despite the fact that their applications
*did* require those things. Someone in authority told them they
didn't and they bought it (and still buy it). Let me clue you in: you
need these things or you need to let someone else handle your
database work for you.
--
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461