So I have a list of about 75,000 items. I want to know if I perform a CAML Query that returns a couple of hundred items, is that going to be slow? (slow = 10+ secs, med = 5-9 secs, fast 0-4 secs) Thanks
You would never know until you try it, why don't you create a webpart and use performance monitor along the side to judge it.
Anyway Your question should be, I need to get several of hundred of items out of list with 75,000 items, so first thing first, how many options you got to get list items, You can use CAML or Linq as you have to use one of them to query items so you should go for fastest one which is CAML as far as I know but they both have there own advantages.
I was reading a blogpost few months back which stated that fastest query will be where you will be using both CAML and Linq to get your list items and then filter through them.
Some of links you might find helpful are given below,
Hope it helps.