Database mirroring provides a database redundancy solution using the log-transfer mechanism. The transaction log records are sent to the mirror transaction log as soon as the log buffer is written to the disk on the principal. Mirroring can be configured in either high-performance mode or high-safety mode. In high-safety mode, if the principal fails, the mirror server automatically becomes a new principal and recovers its database. Understanding application behavior in terms of log-generation rate, number of concurrent connections, and size of transactions is important in achieving the best performance. Network bandwidth plays a very important role in a database mirroring environment. When used with a high-bandwidth and low-latency network, database mirroring can provide a reliable, high-availability solution against planned and unplanned downtime. In Chapter 18, you'll explore the details of the backup and recovery options that SQL Server 2008 provides.