This may be a bit of a noob question, but I'm curious:
How can a database handle multiple simultaneous requests, most notably reads? Is every request placed in a queue, so it really occurs one at a time? Or, with a multicore processor is it possible to actually handle multiple requests at the same time?
I guess an obvious extension to this question then would be: how much does having a multiple core CPU matter to a database server?
I'm specifically thinking about MS SQL Server 2008, but this question is probably applicable to most database servers.