T-SQL Tip 3: NOLOCK Will Lock

NOLOCK is poorly named. You would think it means it doesn’t take locks, but what it really does is ignore other locks. NOLOCK is a shorthand way of using the Read Uncommitted isolation level. This is better named. You can and will read uncommitted records with NOLOCK. This can cause results to be inaccurate because the uncommitted records may ultimately never be committed. Meanwhile NOLOCK can block additional writes from happening because it takes a lock…