Scott writes "I was purusing the SQL Books On-Line and reading about Locking Hints. One of the hints is NOLOCK, which, according to the BOL, the effect of this hint is: "Do not issue shared locks and do not honor exclusive locks. When this option is in effect, it is possible to read an uncommitted transaction or a set of pages that are rolled back in the middle of a read. Dirty reads are possible. Only applies to the SELECT statement."
My question: is there anytime when you wouldn't want to explicitly use this hint? I mean, say you are just selecting something, and it's not vitally important if someone is in the process of updating it... that is, you are using no transactions anywhere on the site. Would explicitly giving this hint in all queries speed up access or query time? A friend of mine is working on a project that has millions of rows in a database table, and uses the NOLOCK hint explicitly, claiming it "increases performance." (Sadly, he didn't give any details beyond this statement...)
Thanks!"
NOLOCK Locking Hint 
Posted - 2000-10-22 : 23:44:25