You can't base performance measurement off of execution plans. The only way to absolutely know which statement in a batch took longer is to have measurements, using extended events or...

If it was running good until Sunday, what changed on Sunday? New code release, service pack, new client, new users? Something had to have happened to it.

Gail, congrats on getting a spot on the new 24 Hours of PASS.

To calculate usage over time, you'd need to gather metrics over time. You can use Permon to do this.

I can also suggest (full disclaimer, I work there) Red Gate's SQL...

I had a UDF I used to use as well. With smaller data sets it works fine. But if you start to grow them, I really suggest using the tally...

What happened to the available bit in Table c?

The thing is, unless you're maintain a history of availability so that all entries to Table B are inserts (in which case...

Take a look at this article by Jeff Moden[/url]. He shows how to use a tally table to solve the problem you're describing. It's a very efficient approach.

I agree. I can't see why you would need to join to that table unless there are other fields and functions you're not showing.

You should be able to, yes. Why not?

We haven't run into anything either. Check the documentation on Microsoft's web site to see what is being changed. Run tests on it prior to running it in production. That's...

You have to make a choice. What does an empty string mean as an integer? Is it NULL? Is it 0? You have to supply something because a number can't...

If you only need the list of UKEY, why are you selecting all the other columns?

Not having all your code to understand completely what's going on, I may get this...

The only suggestion I can make is to start using Roles within the database in addition to AD groups. Yes, if the AD server goes offline it can and does...

It doesn't make any sense that the time would vary, a recompile fixes the time, but you're looking at identical execution plans. Based on the situation you describe, the exec...

There's no way to directly manage the size of cache. If that's all the cache that is getting used, that's all SQL Server needs. I'd double check to be sure...