StorageTek 312564001 manual OTDBP130 - the pre-fetchutility, Clean-upprocessing

the failed execution. No special actions need to be taken prior to re-starting the failed row restore job.

Clean-up processing

Following successful execution of the row restore utility, the storage used in the Archive Manager database for rows which have been restored to DB2 will no longer be accessible, and will be eligible for re-use. However, this space cannot be re-used until the Archive Manager object holding a restored row has been deleted from the Archive Manager database.

As multiple migrated rows may be held in each Archive Manager object, it is not possible to delete the object until all migrated rows held therein have been invalidated (either due to being restored to DB2, or to the row being deleted from the DB2 table).

DB2 Manager provides a database housekeeping utility to perform cross- reference processing between a DB2 table and its associated Archive Manager database, and to delete Archive Manager objects which no longer contain active migrated rows. Standard Archive Manager object management and database maintenance processing can then be performed to allow re-use of index storage and tape and/or disk copy storage used for objects which have been restored. Refer to “Archive Manager database maintenance” on page 114 for a description of Archive Manager database housekeeping processing requirements.

OTDBP130 - the pre-fetch utility

OTDBP130 is the DB2 Manager pre-fetch utility program. The program is executed as a batch job in order to pre-fetch Archive Manager objects containing migrated rows from tape to disk storage within the Archive Manager database. After pre-fetching, the objects containing the selected rows will be accessed from disk instead of from tape, improving performance for access to migrated rows. Note that pre-fetching rows using this utility will not affect the migration status of the rows - these will remain in Archive Manager storage, and are not restored to the originating DB2 table. The row restore utility OTDBP120 should be used if it is required to return migrated rows to DB2 storage.

The rows to be pre-fetched by Archive Manager are identified by the customer via search criteria in an SQL command, in an identical manner to the way in which rows are identified for selection for migration by OTDBP100. Execution of the program is controlled via a series of execution parameters.

A print report is issued by the utility giving details of the execution parameters, the pre-fetch selection criteria and detailed and/or summary information about the rows pre-fetched by Archive Manager.

Disk copies of pre-fetched objects are retained by Archive Manager for the period of time specified in the database definition. Pre-fetched objects will be deleted by the Archive Manager object management utility following

DB2 Manager User Guide	99
StorageTek Proprietary