This is an old article, but it shows one way to deal with versioned and backdated data. It's still very applicable. Also a follow-up article showing another mechanism....

A DELETE operation has to find the appropriate rows to delete. That means it has to look at the values. If there are no indexes, it has to scan every...

Oh, and 2019 introduces a bunch of good knobs for tweaking QS behaviors. You really can reduce the overhead quite a bit (QS is amazing, wonderful and cool, but yeah,...

I normally do try.  I even violated my own decision to "black ball" someone last night and tried to figure out what the heck it was they were talking...

Yeah, Jack's right. Query Store is a good way to go. It does aggregate the data you get (by the hour by default), so if you need detailed info, XE...

I shy away from the ring buffer as an output mechanism. It puts quite the load on the monitored machine. Instead, I'd suggest using file output. You could then use...

I try to help. I really don't look at who it is. I try.

Now, if they get demanding. I walk away. No need to argue or whatever. I helped, or...

As you can tell, this is a huge topic. There's a lot to it. Honestly, I'd suggest you grab a copy of my book, link in the signature below this...

I am not aware of any.

Oh, same query, but not just a single instance of the query. Yeah, totally different. I understood you meant that only the one process and one query was involved. Instead,...

Data.

As data changes, so does behavior. A query that was fine for 10k rows isn't for 10million. Check the execution plans. Look at row estimates there. Compare them to reality....

There are always exceptions to everything, but speaking in general terms, you'll be better off letting SQL Server perform an update through the UPDATE process rather than deleting existing data...

Let's say you're a small organization. You don't have a massive IT budget. Yet, you want a database. Do you now have to hire someone to set up servers, an...

Be real cautious about fixing deadlocks using table lock hints. It may fix the deadlock, but can cause other performance hits. Testing is your friend.

Likely, it's a parallelism deadlock. You'll...

When I see a sudden change in behavior like this, first is checking all the servers & os's, etc., for changes. A new patch on the SAN or on the...