READ COMMITTED
An isolation level that uses a locking strategy that relaxes some of the protection between transactions, in the interest of performance. Transactions cannot see uncommitted data from other transactions, but they can see data that is committed by another transaction after the current transaction started. Thus, a transaction never sees any bad data, but the data that it does see may depend to some extent on the timing of other transactions.
When a transaction with this isolation level performs UPDATE ... WHERE or DELETE ... WHERE operations, other transactions might have to wait. The transaction can perform SELECT ... FOR UPDATE, and LOCK IN SHARE MODE operations without making other transactions wait.
See also ACID.
See also isolation level.
See also locking.
See also REPEATABLE READ.
See also SERIALIZABLE.
See also transaction.