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What is mirroring of database?
A mirror database is a backup copy created on another server to ensure continuous data availability and avoid downtime. With database mirroring, copies of a single database reside on different computers called server instances, typically remote from each other.
What is the meaning of mirror copy?
1 a canon in which the parts are written as though seen in a mirror placed between them: one part or set of parts is the upside-down image of the other. 2 sometimes, less accurately, a piece that can be played backwards.
What do you need to know about Database mirroring?
mirror server. In a database mirroring configuration, the server instance on which the mirror database resides. principal database. In database mirroring, a read-write database whose transaction log records are applied to a read-only copy of the database (a mirror database).
Can a database mirror be used for transactional replication?
Replication supports mirroring the publication database for merge replication and for transactional replication with read-only Subscribers or queued updating Subscribers. Immediate updating Subscribers, Oracle Publishers, Publishers in a peer-to-peer topology, and republishing are not supported.
Do you have to run the same SQL Server as the mirror server?
The mirror server instance must be running the same edition of SQL Server. A database mirroring session runs with either synchronous or asynchronous operation. Under asynchronous operation, the transactions commit without waiting for the mirror server to write the log to disk, which maximizes performance.
Who is the principal server in database mirroring?
In database mirroring, the partner whose database is currently the principal database. Received transaction log records that are waiting on the disk of a mirror server. The principal server and mirror server perform complementary principal and mirror roles. Optionally, the role of witness is performed by a third server instance.