I will be working on a Java project that will ultimately run on a linux
platform and am interested in feedback on the databases typically used
in Java development.  My prior projects have been developed in
Microsoft .Net against Sql Server.

What databases (i.e. MySQL, PostgreSQL, Oracle, etc) will take
advantage of a multi-processor server?  For instance does MySQL simply
not experience any performance advantages running on a multi-processor
system where as Oracle does?

The server will definitely be dual-processor but could even be a
quad-processor I pick up from a prior project.

Any feedback would be appreciated.