data-konzept

'When you’re tuning queries

It’s sort of a relief when the first time you get your hands on it, you get the plan and there’s a missing index request. Even if it’s not a super high-value one, something in there is crying for help. Where there’s smoke, there’s a bingo parlor.

But does adding missing indexes from requests always make things better?

The question goes for any tool, whether it’s DTA, or the missing index DMVs, or your own wild speculation. Testing is important.

Not all requests are helpful

In fact, some of them can be harmful. Let’s look at a recent example from the Orders database. After running for a while, I noticed the UpdateShipped stored procedure was asking for an index. And not just any index, but one that would reduce query costs by 98.5003%. That’s incredible. That’s amazing. Do you take DBA Express cards?'...

https://www.brentozar.com/archive/2017/02/crappy-missing-index-requests/