StorageTek 312564001 User Manual

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88 
DB2 Manager User Guide 
 StorageTek 
Proprietary 
Further executions of the table migration job for the appropriate DB2 table 
may subsequently be performed as normal. 
 
Data management processing 
Following successful execution of a table migration process, a number of 
follow-up activities may be required in order to complete the management of 
migrated and unmigrated data.   These activities consist of the following: 
•  DB2 table backup and recovery 
•  DB2 table reorganization 
•  Archive Manager database backup and recovery 
DB2 table backup and recovery 
There is no change required to backup and recovery processing procedures 
for tablespaces containing tables which have been enabled for DB2 Manager 
migration.   Image-copies should be taken normally as for non-enabled 
tables.   However, as the size of the tablespaces used for storage of tables 
may now have been substantially reduced, the length of time taken for image-
copy processing will be reduced by a corresponding amount. 
Restore of a tablespace containing a migration-enabled table is performed in 
an identical manner to that of a tablespace containing a non-enabled table.  
DB2 will restore the 18-byte stubs containing information about migrated 
rows, as well as restoring non-migrated rows, to the condition they were in at 
the time the image-copy was taken.  The stubs contain all the information 
necessary to access migrated rows from Archive Manager. 
DB2 database reorganization 
Tables which have been enabled for migration processing must be defined in 
a partitioned tablespace (see “Enabling a DB2 table for migration processing” 
on page 75).   This tablespace will have one partition for exclusive storage of 
migrated row stubs, and one or more partitions for storage of non-migrated 
rows. 
Database reorganization processing should not be performed on the partition 
containing the migrated row stubs, unless absolutely necessary.    
Reorganization of this partition will cause all migrated rows to be retrieved 
from Archive Manager.   If Archive Manager objects are held on tape storage 
only, this is likely to generate a substantial amount of tape activity and could 
take an excessive length of time to complete.   However, all rows stored in 
this partition will be a fixed 18 bytes in length.  In this case, deletion of rows is 
not likely to cause fragmentation in the tablespace, as deleted space can be 
re-used as required.   The requirement for reorganization of this partition is 
thus not mandatory.