In this chapter, we introduced you to the disaster recovery discipline with the whole big picture of business continuity on SQL Server. Disaster recovery is not only about having backups, but more about the ability to bring the service back to operation after severe failures.
We have seen several options that can be used to implement part of disaster recovery on SQL Server--log shipping, replication, and mirroring. All three features are still in use today, although mirroring is being retired in many environments and replaced with the more flexible Availability Groups, which will be discussed in another chapter.
In the next chapter, we'll focus on indexing strategies and introduce various index types that you can use to optimize the performance of your SQL Server environment.