postgres vs mysql

MySql is to Postgres as cvs is to Clearcase.

MySql is easy to use and works (as does cvs)

A developer can get their hands around all of MySql. It works as advertised. It is fast. It is easy to install, maintain and use. It has no surprises, other than some non-standard SQL constructs. No surprises is a good thing because we aren't all DBAs, and we really don't want to be. Users and programmers love MySql, it matches what they think a DB should be.

Postgres is byzantine (as is Clearcase)

Too many surprises. Too big. Too slow. Too many cooks^h^h^h^h programmers had a hand in it and it shows. Yes, it does support the SQL standard a little better than MySql. But to get that, you pay the pain of maintaining it. DBAs love postgres, it matches their model of what a DB should be.

Save yourself a lot of hassle; use MySql (and cvs, svn, arch etc. but not Clearcase)