CHAPTER 8 n DATABASE MIRRORING 227
Database Snapshots
One of the most useful and potentially problematic features of SQL Server is the database
snapshot. It provides two basic pieces of functionality: 1) a point-in-time view of a
database (a data time machine, if you will) and 2) the ability to restore the production
database to that point in time extremely quickly. However, a database snapshot is not
part of, nor should it ever be a part of, a backup/recovery process. It needs a live database
in order to function. It can play an important role in a disaster recovery plan, though.
In this chapter, I??™ll examine the architecture of database snapshots, their practical
usage, and how they play into a disaster recovery plan. There are many creative uses for
database snapshots other than disaster recovery scenarios. I??™ll mention some of these
uses briefly, because they can conflict with disaster recovery using database snapshots.
Understanding the Architecture
For practical purposes, a database snapshot behaves just as a read-only database; its
implementation, however, is quite different.
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