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Finding Unique Key Violations with Extended Events

Grant Fritchey points out another use for extended events:

Most of the time when I talk about or demo Extended Events, I spend more time talking about query tuning (I have a problem). However, there are tons of things that you can do with Extended Events. Here’s a little one that came up, auditing unique constraint violations.

It can also handle most other types of errors, making this a robust way of tracking issues. Back in the 2008 days, I built a little WPF program to watch for all of the errors on the couple of production SQL Server instances I managed. At one point, I saw one of the devs trying to write a query and getting an error. I IM’d the dev and said “You forgot the GROUP BY clause” (or whatever the problem was—it was something minor like that). He came over with a bit of panicked excitement, trying to figure out how exactly I was able to see what he wrote given that I was nowhere near his cube. Good times.