Database Mirroring
Database Mirroring is a high-availability and disaster recovery solution primarily used in Microsoft SQL Server to maintain a standby copy of a database on a separate server instance. It works by continuously transferring transaction log records from a principal database to a mirror database, ensuring the mirror stays synchronized and can quickly take over if the principal fails. This technology provides automatic failover capabilities with minimal data loss, making it suitable for critical applications requiring high uptime.
Developers should learn Database Mirroring when building or maintaining SQL Server-based systems that demand high availability, such as financial services, e-commerce platforms, or healthcare applications, to minimize downtime during server failures. It is particularly useful in scenarios where rapid failover (within seconds) and data redundancy are critical, though it has been largely superseded by newer technologies like Always On Availability Groups in modern SQL Server versions. Understanding Database Mirroring is essential for legacy system maintenance and migration planning.