Contents Index Understanding backups The transaction log

ASA Database Administration Guide
  Backup and Data Recovery
    Understanding backups

The database file


When a database is shut down, the database file holds a complete and current copy of all the data in the database. When a database is running, however, the database file is generally not current.

The only time a database file is guaranteed to hold a complete and current copy of all data is when a checkpoint takes place. At a checkpoint, all the contents of the database cache are written out to the disk.

The database server checkpoints a database under the following conditions:

Between checkpoints, you need both the database file and another file, called the transaction log, to ensure that you have a complete copy of all committed transactions.

For more information about checkpoints, see Checkpoints and the checkpoint log, and How the database server decides when to checkpoint.


Contents Index Understanding backups The transaction log