8. Backup and Recovery

Altibase data can be lost due to unforeseen incidents such as system failure, a disk fault, a data file loss, etc. This chapter describes the backup and recovery features of Altibase for use in preparing for such incidents.

Altibase Backup Policy

Logical backup procedures are as follows:

• Logical backup procedure

  Utility Backup

• Physical backup procedure

  Offline backup

  Online backup

Logical backup refers to the use of a utility such as iLoader to create a logical copy of a database object and save it as a text file. Logical backups may not be able to recover to the point of failure.

Physical backup refers to copying the data files and log anchor files that make up the database to a separate disk or tape. Physical backups are divided into online backups and offline backups depending on whether the service is interrupted while copying a snapshot of the data file.

An offline backup is a copy of all tablespace files, log anchor files and log files after normal shutdown of the database server.

Online backup refers to copying data files and log anchor files in the database without service interruption. Uncommitted data may be backed up during the copying of data files. Therefore, log files are needed to undo these uncommitted transactions during recovery. Therefore, online backup is possible only when operated in the archive log mode in which the archive log files are generated.

Altibase Recovery policy

Altibase supports the following recovery types:

• Logical backup recovery

• Restart Recovery

• Media Recovery

Logical backup recovery is the recovery from backup text files using the iLoader utility. Restart recovery is a simple recovery method that is automatically initiated when an Altibase server is restarted. Restart recovery is conducted after a database server has been abnormally terminated.

Media recovery uses database files, log anchor files, and archive log files that were created based on the backup policy to recover database files either to the most recent backup or to a specific moment in time ("point-in-time recovery"). Depending on the kind of ../img error and the recovery procedure, the database may be recovered using either complete recovery or incomplete recovery, as appropriate.

For more detailed information about backup and recovery, please refer to the Administrator's Manual > Chapter 10. Backup and Recovery.