StorageTek 312564001 manual OTDBP100 - the table migration utility

OTDBP100 - the table migration utility

Migration of rows from a DB2 table to Archive Manager storage is performed using the DB2 Manager table migration utility. This is executed as a batch job, and processes a single DB2 table per execution. An SQLIN dataset entry is used to specify the selection criteria for migration of table rows. This is specified in the form of an SQL SELECT command. Refer to “SQLIN entry specification“ on page 85 for a description of the specification and usage of this entry.

Rows from a single DB2 table will be stored in a single Archive Manager database (identified to the utility via the SQLIN file). In addition, an Archive Manager database may only contain rows from a single DB2 table. DB2 Manager enforces this one-for-one relationship between DB2 table and Archive Manager database during execution of the table migration utility.

Multiple table migration jobs can be executed concurrently. However, each job must process a different DB2 table – only one table migration procedure per DB2 table is permitted at any one time. The table migration utility communicates directly with the DB2 Manager control region in order to connect and disconnect the Archive Manager database being updated. Note that the DB2 Manager control region must be fully initialized prior to the start of table migration processing.

A control region writer task will be assigned to the procedure during this process. This task will store migrated rows in Archive Manager objects on the latest tape dataset in storage level 0 of the Archive Manager database. No other writer task may connect to the Archive Manager database for update processing while this is in progress.

In addition, tape reader tasks will not be able to satisfy retrieval requests for migrated rows stored in objects on the tape volume being updated by the writer task. A ‘resource unavailable’ error (SQL –652 error and a reason code of X’1015’ in field SQLERRD(6) in the SQLCA) will be returned to an application program which generates such a request. If access to such rows is required, it is recommended that Archive Manager (‘K’) copy processing be enabled in order to hold copies of objects from at least the latest tape volume in the database storage level on disk. This will permit retrieval of these objects using control region disk reader tasks. Alternatively, the Archive Manager “dynamic load balancing” facility could be implemented in order to satisfy retrievals from the appropriate backup volume, if available. Refer to the Archive Manager User Manual for a description of both these facilities.

Note that retrieval of migrated rows from objects held on tape volumes other than the latest in the database storage level will be able to continue without interruption while table migration processing is in progress for that Archive Manager database.

80	DB2 Manager User Guide
	StorageTek Proprietary