# Part two: Derby Administration Guide

This section of the guide is divided into several administrative tasks.

- Checking database consistency
  If you experience hardware or operating system failure, you can use the SYSCS_UTIL.SYSCS_CHECK_TABLE function to verify that the database is still consistent.
- Backing up and restoring databases
  Derby provides a way to back up a database while it is online. You can also restore a full backup from a specified location.
- Replicating databases
  Replication is an important feature of a robust database management system. In Derby, you start database replication by using connection URL attributes.
- Logging on a separate device
  You can improve the performance of update-intensive, large databases by putting a database's log on a separate device, which reduces I/O contention.
- Obtaining locking information
- Reclaiming unused space
  A Derby table or index (sometimes called a conglomerate) can contain unused space after large amounts of data have been deleted or updated.