Database Mirroring Overview

Abstract

Database mirroring was introduced in SQL Server 2005 and provides multiple levels of protection depending on the configuration you choose for your environment. Database mirroring is the practice of keeping two copies of your database synchronized with each other so that if you lose one copy, you can continue work with the other. If you have ever worked with log shipping, you should be familiar with many of the concepts in database mirroring. In fact, database mirroring in its early stages was referred to as real-time log shipping or dynamic log shipping. You will see however, that database mirroring is a far more robust and enterprise-level solution than is log shipping. For example, prior to database mirroring, if you had wanted a solution that ensured zero data loss, your only option would have been failover clustering. This chapter will cover all the components that make database mirroring tick. Sure, you can set up database mirroring using a wizard and move on with life. But, since you are reading an entire book dedicated to database mirroring, something tells me you want to know what is going on under the hood.