DB Clustering Question

Hi everyone, I'm new to this list.  I'm researching database cluster
solutions and I'm not really finding what I'm looking for.

What I really want to do is parallel processing with mySQL or
Postgresql.  If I can't do that, then simply having multiple SQL servers
share the same DB files is the next option.  Can anyone push me in the
right direction?

One last question, does anyone have any experience with the Ingres
database and its clustering features?

-- 
Matt <mrc@xxxxxxxxxxxxxxxxx>