Separating Data and Log Segments

In most cases, it is recommended that you store transaction logs on a separate database device and segment from the actual data. It is important to separate these segments because:

• It enables you to save transaction log dumps.

  If the data and log are on the same segment, you cannot save transaction log dumps, so up-to-date recovery after a media failure is not possible. For details about backup and recovery, see Chapter 12, "Backing Up and Restoring."

• It increases performance for logged operations.

  If you place the data and log segments on different physical devices, such as different disks and controllers, I/O requests for a database are divided between two devices.

• It enables you to determine the amount of log space used.

  Use Performance Monitor to determined the amount of log space used. Performance Monitor provides a quick and convenient way to monitor log space.