REPEATABLE READ

I'm about to do a couple of posts comparing MSDE against SQL Server Express (or, as I like to call it, SQLE).

In these posts I'll cover the facts about MSDE -- in an easy to digest form (I have such a hard time keeping the details straight myself -- I'm sure that others do as well -- so having a simple list of what MSDE does and doesn't do will be handy).

I'll also cover a bit of what the Workload Governor does, and how to tell when it's time to pony up $$ and pay for your SQL Server habit.

Finally, I'll cover the limitations in SQLE against those in MSDE -- suffice it to say that SQLE blows MSDE out of the water (but you already knew that).

However, before I start, I have to cover:

MSDE Workload Governor: Eight Concurrent Operations, or Five?
For the longest time, Books Online, and other supporting documentation stated that the workload governor in MSDE and SQL Server Personal Edition limited concurrent batches to five before kicking in.
Docs updated in January of 2004, out on the MS site state that the number is eight batches.
The newer docs, are of course right. Moreover, it looks like this WASN'T a change that got slipped in with service packs anywhere -- I did a fresh install of SQL Server 2000 (without service packs), ran a few looping queries and managed to throw concurrency violations, and then checked my Application Log. Sure enough, I was told:
"This SQL Server has been optimized for 8 concurrent queries. This limit has been exceeded by 3 queries and performance may be adversely affected."

So the moral of the story, always trust the docs -- when they are correct.