WITH (NOLOCK) still places locks !

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Did you know, that when you use READ UNCOMMITTED isolation level or WITH (NOLOCK) hint inside the query, it is still places Sch-S (schema stability) locks during compilation and execution and can be blocked by any concurrent trancastion that that holds a Sch-M (schema modification) lock on the table!
So, when using READ UNCOMMITTTED isolation level, keep in mind that READUNCOMMITTED and NOLOCK hints apply only to the data locks and there is nothing you can do with Sch-S lock.

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