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Procedure documentation Developing Good Practice for Archive (ON-Archive and ontape)  Locate the document in its SAP Library structure

Use

This section discusses guidelines for creating Informix database archives with ON-Archive or ontape .

Procedure

  1. Archive with the Informix database server in online mode.

    2. You can archive while the Informix database server is fully online and no extra risk is involved. Data consistency is maintained, which means that you can restore the database correctly (to the point the archive was started) without using logical-log files, unlike some other database systems. The exception to this is parallel archives, which require the logical-log files to be present if a restore is later necessary. Always follow a parallel archive with a logical-log file backup.

    You can archive in quiescent mode, but this is normally unnecessary. You cannot archive in offline mode. For more information about Informix database server modes, see Server Mode with SAPDBA and the Informix documentation.

  2. Archive during off-peak hours.

    3. An archive, particularly one that uses software compression, can affect the performance of the Informix database server. Since performance of your database is critical, it is best to do your archives during off-peak hours.

  3. Perform a full archive when necessary.

Sometimes, you must perform a full (level-0) archive in sequential mode. The Informix documentation provides information about database administration activities requiring such full archives.

For example, you have to perform a full database archive after changing the configuration of the physical and logical logs. Full archives are also required with Reorganize Single Table, Reorganize Group of Tables and Reorganize Dbspace in SAPDBA. You are also strongly advised to do a full archive after performing an emergency backup of the logical log. Refer to Emergency Logical-Log Backup. For a summary of measures you can take to avoid the problem of emergency logical-log backups, see Preventing Emergency Logical-Log Backup.

Result

The database is archived using best practice, so avoiding impact on the production system as far as possible. Therefore, you can be more sure that, in the event of failure involving data loss, you have a suitable archive that you can use to quickly restore the database with minimal data loss.