Administration Guide

Enabling Utility Parallelism

This section provides an overview of how to enable intra-partition parallelism for the following utilities:

• Load
• Create index
• Backup database / table space
• Restore database / table space

Inter-partition parallelism for utilities occurs automatically based on the number of database partitions.

Load

The Load utility automatically makes use of parallelism, or you can use the following parameters on the LOAD command:

• CPU_PARALLELISM
• DISK_PARALLELISM

Refer to the Data Movement Utilities Guide and Reference for information on the LOAD command.

AutoLoader

You can enable multiple split processes for the AutoLoader by specifying the MODIFIED BY ANYORDER parameter for the LOAD specification in the autoloader.cfg file. Refer to Administration Guide, Performance for more information on this LOAD specification and the configuration file.

Create Index

To enable parallelism when creating an index:

• The INTRA_PARALLEL database manager configuration parameter must be ON
• The table must be large enough to benefit from parallelism
• Multiple processors must be enabled on an SMP machine.

Refer to the SQL Reference for information on the CREATE INDEX statement.

Backup Database / Table Space

To enable I/O parallelism when backing up a database or table space:

• Use more than one target media.
• Configure table spaces for parallel I/O.
• Use the PARALLELISM parameter on the BACKUP command to specify the degree of parallelism.
• Use the WITH num-buffers BUFFERS parameter on the BACKUP command to ensure enough buffers are available to accommodate the degree of parallelism. The number of buffers should equal the number of target media you have plus the degree of parallelism selected plus a few extra.

  Also, use a backup buffer size that is:

  • As large as feasible. 4 MB or 8 MB (1024 or 2048 pages) is a good rule of thumb.

  • At least as large as the largest (extentsize * number of containers) product of the table spaces being backed up.

Refer to the Command Reference for information on the BACKUP DATABASE command.

Restore Database / Table Space

To enable I/O parallelism when restoring a database or table space:

• Use more than one source media.
• Configure table spaces for parallel I/O.
• Use the PARALLELISM parameter on the RESTORE command to specify the degree of parallelism.
• Use the WITH num-buffers BUFFERS parameter on the RESTORE command to ensure enough buffers are available to accommodate the degree of parallelism. The number of buffers should equal the number of target media you have plus the degree of parallelism selected plus a few extra.

  Also, use a restore buffer size that is:

  • As large as feasible. 4 MB or 8 MB (1024 or 2048 pages) is a good rule of thumb.

  • At least as large as the largest (extentsize * number of containers) product of the table spaces being restored.

  • The same as, or an even multiple of, the backup buffer size.

Refer to the Command Reference for information on the RESTORE DATABASE command.

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