# Exclusive locks

When a statement modifies data, its transaction holds an exclusive lock on data that prevents other transactions from accessing the data.

This lock remains in place until the transaction holding the lock issues a commit or rollback. Table-level locking lowers concurrency in a multi-user system.

Parent topic: Types and scope of locks in Derby systems
Related concepts
Shared locks
Update locks
Notes on locking
Related reference
Lock compatibility
Scope of locks