Locking granularity

The level and type of information that the lock protects is called locking granularity. Locking granularity affects performance.

When a user cannot access a row or key, the user can wait for another user to unlock the row or key. If a user locks an entire page, a higher probability exists that more users will wait for a row in the page.

The ability of more than one user to access a set of rows is called concurrency. The goal of the database administrator is to increase concurrency to increase total performance without sacrificing performance for an individual user.