Reorganization 

Before scheduling a REORG job, you should make sure that you have a resonably recent backup of the system for disaster recovery.

The REORG job allows the reorganization (by partition, if required) of an SAP tablespace or index during online operation. This means you have both read and write access during the reorganization (SHRLEVEL CHANGE).

Special Considerations for LOB Tablespaces

Note that for LOB tablespaces, an online REORG is not possible and therefore SHRLEVEL NONE is defined. If at least one of the tablespaces, you intend to reorganize, is a LOB tablespace, you are informed. We recommend that you upload the job to z/OS and submit it only during a maintenance window, when the SAP system is down.

For all tablespaces upon which inline RUNSTATS is allowed, inline statistics are generated.

Extents

If the number of extents of the corresponding data sets is larger than four, then the actual REORG is proceded by an ALTER on the primary and secondary quantity as a separate job step, so that the table or indexspace shows a maximum of four extents after the reorganization. As many sort work and data work datasets are provided as needed.

When a Mapping Table is Necessary

When performing an online reorganization of a tablespace (not an index), you need to create a mapping table (see the IBM documentation DB2 UDB for z/OS Utility Guide). SAP automatically creates a tablespace DSNDB04.QT<nnnnnn> with the stogroup MAPZZQAA. <nnnnnn> is a six digit number. In this tablespace, a table QT<nnnnnn> with a unique index QX<nnnnnn> is created. These tablespaces are reused for faster performance.

To ensure that the CREATE statments run error-free, you must make sure that the stogroup MAPZZQAA exists.

The names QT<nnnnnn> or QX<nnnnnn> are reserved for this application. Do not use these names to create any tablespaces, tables or indexes.

Profile Parameters for REORG

The following profile parameters exist for the reorganization. You maintain these with the JES Interface (transaction DB2J), function Profile parameters:

Storage Parameters

·        HLQ for Backup data sets

·        HLQ for work data sets

·        MGMTCLAS (SMS)

·        STORCLAS (SMS)

·        DATACLAS (SMS)

·        Volume count

Overwrites the value defined in DATACLAS, if necessary.

·        Number of GDG generations:

If a value bigger than zero is specified, then the copy and work data sets are allocated as GDGs. For more information about GDG generation, see Backup.

General

·        DB2 run library

Library containing the program DSNTIAD

·        Plan of program DSNTIAD

REORG-specific parameter (choose REORG)

·        Number of parallel jobs

·        Size of work datasets/unload dataset:

Space requirement grows with the number of indexes; default 2, increase if
necessary.

·        Default action when submitting “REORG on suggested tablespaces” non-periodically:

When REORG on suggested tablespaces is planned periodically, LOB tablespaces are not included into the job, because on them ONLINE REORG is not possible and severe performance impact on the running SAP system would be the result.

When planning this action non-periodically, you can configure here if LOB tablespaces are to be included or not. If the job at time of planning will contain a LOB tablespace, a warning will pop up. Before running the job, please consider to take a recent backup of the system and to upload the job, so you can shutdown SAP system previously.

·        Which COPY options are to be used:

You can specify if a remote copy should be taken, as well.

The REORG jobs use data from the table and index monitor.

REORG ALL indexes and tablespaces uses the same parameters as a single REORG.