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80 DB2 Manager User Guide
StorageTek Proprietary
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.