I have a SQL server 2000 instance which runs several concurrent select statements on a group of 4 or 5 tables. Often the performance of the server during these queries becomes extremely diminished. The querys can take up to 10x as long as other runs of the same query, and it gets to the point where simple operations like getting the table list in object explorer or running sp_who can take several minutes.

I've done my best to identify the cause of these issues, and the only performance metric which I've found to be off base is Average Latch Wait time. I've read that over 1 second wait time is bad, and mine ranges anywhere from 20 to 75 seconds under heavy use.

So my question is, what could be the issue? Shouldn't SQL be able to handle multiple selects on a single table without losing so much performance? Can anyone suggest somewhere to go from here to investigate this problem?

Thanks for the help.