Although each function can be discussed separately, they are mutually dependent. Both concurrency control and recovery are required to protect the database from data inconsistencies and data loss. Many DBMSs allow users to undertake simultaneous opera-tions on the database. If these operations are not controlled, the accesses may interfere
with one another and the database can become inconsistent. To overcome this, the DBMS
implements a concurrency control protocol that prevents database accesses from inter-fering with one another.