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Procedure documentationConfiguring Log Partitions Locate this document in the navigation structure

 

To increase the speed with which the system writes log entries to the log area, you can divide the log area into several log partitions. The system can then write log entries to several log partitions in parallel.

A log partition consists of one or several log volumes and, if applicable, the respective mirrored log volumes (if you have enabled software-based mirroring of the log area).

When you create a log volume, you assign it to a log partition. If you do not assign the log volume to a partition, the system automatically assigns it to the first log partition.

Caution Caution

After a log volume is in use, you can no longer change its assignment to a log partition.

End of the caution.

Prerequisites

  • You are logged on to the database as the database system administrator or as a DBM operator with server authorization for accessing database parameters (read and write) (see Glossary, Server Permission).

  • To configure the maximum number of log partitions, use the special database parameter MaxLogWriterTasks (see Changing Database Parameters).

  • Overwrite mode for the log area is off (see Activating or Deactivating Overwrite Mode for the Log Area).

  • During log partitioning you have to carry out a log backup. Note that a log backup requires that you have carried out a complete data backup before (see Backing up Data).

  • The database is in the OFFLINE operational state.

Procedure

Configuring Log Partitions and Activating Log Partitioning
  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose   Administration Tasks   Change Log Settings...  

  3. Select Configure Log Partitioning.

  4. Choose Next.

    If no complete data backup is found, activating log partitioning is not possible. Choose Backup to perform a complete backup if necessary.

  5. Activate Log Partitioning: Activating log partitioning involves carrying out a log backup and restarting database.

  6. Specify the number of log partitions. Select Restart database after configure log partitioning.

  7. To configure log partitioning the database must be in operational state OFFLINE. Select OFFLINE if necessary. After changing the operational state choose Next.

  8. Assign at least one log volume to each of your log partitions.

    To add a log partition, choose New... in the context menu of the log volume.

    To change the log partition that a volume is assigned to, choose Edit... in the context menu of the log volume.

    Recommendation Recommendation

    All log partitions have the same size and the same number of assigned log volumes.

    End of the recommendation.
  9. Create a log backup (Backing Up Log Entries) and choose Next.

  10. To apply your settings, choose Activate.

Changing the Number of Log Partitions
  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose   Administration Tasks   Change Log Settings...  

  3. Select Configure Log Partitioning.

  4. Select Change the number of log partitions.

  5. Specify the number of log partitions.

  6. Assign at least one log volume to each of your log partitions.

    To change the log partition that a volume is assigned to, click on the partition number and use the arrow buttons.

    Recommendation Recommendation

    All log partitions have the same size and the same number of assigned log volumes.

    End of the recommendation.
  7. To apply your settings, choose Activate.

Deactivating Log Partitioning
  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose   Administration Tasks   Change Log Settings...  

  3. Select Configure Log Partitioning.

  4. Select Deactivate log partitioning.

  5. Specify the number of log queues that you want to use.

  6. Transfer the database to the OFFLINE operational state.

  7. Create a log backup.

  8. To apply your settings, choose Activate.

More Information

Adding Log Volumes

Concepts of the Database System, Log Area.