Definition - What does Database Mirroring mean?
Database mirroring is the process of creating and managing multiple copies of a database for the purpose of database backup, recovery and/or performance optimization.
It is a type of data backup and business continuity process that utilizes mirrored instances to enhance database availability and provide a database failover mechanism.
Techopedia explains Database Mirroring
Database mirroring is primarily used to create redundant instances of a database system. These redundant copies help in ensuring database service delivery even if the primary database is offline or unavailable.
Typically, database mirroring is achieved by creating and deploying an instance of a database on two servers, where one acts as the primary database and other as the mirrored database. Each transaction performed on the primary server is instantly copied on the mirrored database server. If the primary server fails, database operations can instantly be transferred to the mirrored database.