One of our SQL Server workloads runs many concurrent parallel queries on a possibly already busy server. Other work occurring on the server can have dramatic effects on parallel query runtimes. One way to improve scalability of parallel query runtimes …
Let’s Have Fun
I got asked recently if there’s a way to find parallel queries that are potentially skewed.
One thing that you’ll see quite often is that duration and cpu time aren’t much different. For parallel queries, it should …
I see people using OUTPUT to audit modifications from time to time, often because “triggers are bad” or “triggers are slow”.
Well, sometimes, sure. But using OUTPUT can be a downer, too.
Let’s look at how.
There are lots of great options out there for figuring out what’s happening on a server. If you’re the kind of person still running sp_who, or sp_who2, or sp_who8045, it’s time to stop.
You’ve got much better options, …
In dramatic fashion, I’m revisiting something from this post about stats updates.
It’s a quick post, because uh… Well. Pick a reason.
Get In Gear
Follow along as I repeat all the steps in the linked post to:
Don’t Want None
One of the many current downsides of @table variables is that modifying them inhibits parallelism, which is a problem #temp tables don’t have.
While updating and deleting from @table variables is fairly rare (I’ve seen it, but …
When you’re measuring query changes to see if your performance changes have made a difference, a common way to do that is to use STATISTICS TIME and IO.
They’re not perfect, but the barrier to entry is super …