Pure speculation and more than a couple of assumptions... The chance for a page split is higher when updating the wider table, so over time, accumulated, the update cost is...

It could be badly written queries. It could be out of date statistics leading to poor execution plans. It could be incorrectly configured indexes. It could be....

Request for the brain trust here on the thread. I'm researching an article on the plan at Heathrow airport for dealing with snow. I'm fairly certain it's published somewhere, but...

Sometimes, not always, an OR causing slow behavior can be replaced by two copies of the query combined using UNION ALL. Not seeing the details here I don't want to...

The reason for something like this is the queries being sent to your system. You need to capture those queries. I'd suggest one of two approaches. First, the most accurate,...

I agree with everything Alan said. I would test both. It sounds like a filtered index is likely to work better for you, but test both to be sure. Just...

Resource DB is a little different. Here's an article on it.

I pointed you to this bit of documentation once before. I'd suggest reading all through it. It's going to help you quite a bit with Azure SQL Database.

A GIANT pinch of salt. The missing index DMVs do not relate the suggested indexes back to queries in any way. You may have a suggestion for an index for...