ROLLBACK
A transaction is being undone by rolling back the changes applied during its execution.
Detailed Description​
Transaction rollbacks are triggered for a number of reasons. The most common being a user requested rollback through to maintain application integrity. Another reason is timeouts - whether this be within the database or a middle tier timeout. Deadlocks will also cause rollbacks, where one of the sessions in the ‘deadly embrace’ scenario will be killed.
Rollbacks are usually single threaded and therefore can take longer than expected.
Re-running you transaction from another session will result in a wait if the rollback has not completed.
How to reduce this wait​
Not available yet. Contributions welcome.
Additional Links​
Microsoft Docs - sys.dm_os_wait_stats (Transact-SQL)
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