Committed Read isolation

A reader with the Committed Read isolation (or ANSI Read Committed) isolation level checks for locks before returning a row. By checking for locks, the reader cannot return any uncommitted rows.

The database server does not actually place any locks for rows read during Committed Read. It simply checks for any existing rows in the internal lock table.

Committed Read is the default isolation level for databases with logging if the log mode is not ANSI-compliant. For databases created with a logging mode that is not ANSI-compliant, Committed Read is an appropriate isolation level for most activities. For ANSI-compliant databases, Repeatable Read is the default isolation level.