While we're all speaking techie here, I've been dying to ask you what your database backend is. I assumed it was Oracle. I'm guessing it wouldn't be MS SQL Server for the load. How big is your database?
I'm an experienced & certified Sybase DBA, also working a little with Oracle and Microsoft SQL Server (the latter being the same as Sybase at one time). Hence the curiosity about your database.
MySQL, it's been good to us and has a choice of storage engines each with different features. We're using the MyISAM storage engine for everything right now, but it's starting to show signs of contention (MyISAM is really good at heavy writing or heavy reading, but not both) so I'll probably start migrating some tables to InnoDB which handles contention better (and does transactions too.)
Oh, the DB is around 30 GB, with another 7 GB of compressed archives which are flat files (actually just HTML.) Those are the older /forum/ URLs you might see from time to time. 2001 and earlier.