A clustered index actually defines data storage. You can have one or more columns as the key for the clustered index, but you won't get any INCLUDE columns in there...

Please, do what Lowell says. Normally, I wouldn't bother answering since he's already provided the correct path. However, I sense the need to pile on. 

You're working with a...

In addition to the other checks listed (blocking, waits, execution plan), are these delete statements deleting varying amounts of data? If the data changes, so will the behavior, sometimes radically...

I'm pretty sure this is utterly impossible. About the only tool you have at your disposal around stuff like this are plan guides. You can force behaviors through hints or...

Both statements are part of a transaction. It's not that the SELECT is holding the UPDATE, it's that the UPDATE and the SELECT are executing as a set of operations.

If you want to monitor for specific security changes, I'd suggest using extended events and then you'll need to filter for statements that are changing the permission on the user....

I hate to say it, but I don't know that I want to get tied down to doing it the same way every time regardless. 

I mean, for stored...

You want to use the function sp_create_plan_guide. The basics are pretty simple. Copy your query, and it has to be a perfect copy, including all the white space...

Actually one other thing does come to mind. You could try using Plan Guides to force the good plan. On a query this complex and a plan this big... It...

These queries are pretty huge. Trying to unpack it all will take a lot of time. I'll focus on one thing. Both plans are timing out in the optimizer. Timeouts...

Linked servers are, unfortunately, a very widely used practice. They're not a very widely recommended practice because of all the issues that they cause. However, they're so very convenient, making...