You know what your deadlock graphs need? Animation.

Deadlocks
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In SQL Server Management Studio, plain ol’ deadlock graphs look like this: Two thumbs down, would not lock the dead again BOOOOO-RING. That’s why I prefer opening deadlock graphs in SentryOne Plan Explorer, which presents a much better visual in the form of a circle…a circle, let’s just stop there: Deadlock graph in SentryOne Plan…
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Brent getting caffeinated

How to Troubleshoot Blocking and Deadlocking with Scripts and Tools

Deadlocks, Monitoring, sp_BlitzLock
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When you need to find which queries are blocking other queries, your decision comes down to when the blocking happened. Is it happening now, recently, or coming up soon? During a live emergency, start with sp_WhoIsActive. Adam Machanic’s excellent free sp_WhoIsActive replaces Activity Monitor, sp_who, and sp_who2, and it’s way more powerful. The documentation is extensive –…
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sp_BlitzLock showing deadlocks

How to Create Deadlocks and Troubleshoot Them

Deadlocks
5 Comments
Watch in awe and wonder as I create a deadlock, then use sp_BlitzLock after the fact to show you which queries and tables were involved: Here are the scripts to run in the left hand window: Transact-SQL CREATE TABLE dbo.Lefty (Numbers INT PRIMARY KEY CLUSTERED); INSERT INTO dbo.Lefty VALUES (1), (2), (3); CREATE TABLE dbo.Righty…
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SQL Server Training by Kalen Delaney

Concurrency Week: Can SELECTs Win Deadlocks?

Deadlocks
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Yes, especially when they’re part of a larger transaction. In this example, I’m going to use a database in Read Committed Snapshot Isolation (RCSI), my favorite isolation level for building new applications from the ground up. Optimistic concurrency (aka MVCC) helps avoid a lot of blocking issues – but not all of them. In a…
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