NOLOCK vs. Transaction Isolation Level

Question

What\'s the difference between using \"SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED\" and NOLOCK? Is one better than the other?

Answer 1

NOLOCK is a query hint and as such only applies to the specifc table within the query in which it is specified.

Setting the transaction isolation level applies to all code executed hence forth within the current connection or until it is explicitly modified.

To clarify, functionally the isoloation level at work is the same however the scope which is covered may not be.