Recovery with SAP MaxDB
Use
To minimize the downtime of your SAP MaxDB database, you must make sure that you can quickly restore the database in the event of a system failure in which productive data is lost. A database can only be recovered in ADMIN operational state using Database Studio.
Prerequisites
When recovering data you must restore (the sequence is important):
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The last complete data backup in either ONLINE or ADMIN state. This step is mandatory.
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Subsequent incremental data backup, if available.
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Any required log backups . Database Studio prompts you for the correct sequence of log backups.
Process
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You design a recovery strategy and test it.
Think in advance what must be done if the database suddenly fails and the data must be restored. Plan the steps carefully and rehearse the procedure using a test system. This substantially reduces downtime later.
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You use the recovery report in the SAP system.
You can obtain a list of the data backups (complete and incremental) and log backups required for a recovery by using the DBA History in the SAP system. Print this report regularly, so that you have an up-to-date list of the required backups, if a recovery is later necessary.
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You make sure that you can quickly identify the tapes required.
To recover the database, you must know exactly which types of backup data carriers you need (that is, complete data backup, incremental data backup, or log backup data carriers). A data backup (including incremental data backups) can consist of several data carriers. You do not have to start restoring data with the first backup nor do you have to finish with the last one. As long as the data carriers belong to the same backup (complete or incremental, parallel or not) the sequence of the media is not important. You can use Database Studio to display the media information.
However, you must restore the individual data backups in the correct sequence. To restore the log entries, you must restore the backups in the correct sequence (that is, in the sequence in which the log backups were performed).
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You choose the fastest recovery strategy.
Start with the recovery of data backups. It is normally faster to restore incremental backups than to restore log backups. To reduce the time needed still further, consider using parallel recovery, that is, with several backup devices working simultaneously in parallel. If you are using incremental backups as well as log backups, you must use the incremental backups first, followed by the log backups.
When recovering a database, you normally need to restore log backups too. Sometimes the relevant log entries are still in the log area (that is, they have not yet been backed up). In this case the log recovery does not take place explicitly. The relevant log entries are restored when the database is restarted. If there are log entries required for recovery but these are no longer in the log area, the system guides you accordingly.
More Information
Restoring Databases in Database Administration