How to Select UNCOMMITTED rows only in SQL Server?

sql sql-server tsql isolation-level transaction-isolation
BI Dude picture BI Dude · Mar 7, 2014 · Viewed 27.9k times · Source

I am working on DW project where I need to query live CRM system. The standard isolation level negatively influences performance. I am tempted to use no lock/transaction isolation level read uncommitted. I want to know how many of selected rows are identified by dirty read.

Answer

usr picture usr · Mar 7, 2014

Maybe you can do this:

SELECT * FROM T WITH (SNAPSHOT)
EXCEPT
SELECT * FROM T WITH (READCOMMITTED, READPAST)

But this is inherently racy.

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