Altering the size attributes of an active DEDB area with the DEDB Alter utility

You can alter the DEDB area definitions of the SIZE, UOW, and ROOT parameters for an active DEDB area to increase the size of the DEDB area while the DEDB area remains accessible online by using the DEDB Alter utility (DBFUDA00).

1. Update the size attributes of the active DEDB area.
   • If you use the DBDGEN utility, update the AREA statement with any changes to the SIZE, UOW, and ROOT parameters, as necessary.
   • If you use DDL, use the ALTER TABLESPACE statement with the SIZE PRIMARY, UOW, and ROOT parameters, as necessary.
2. If you are adding one or more fields to existing free space that is in a segment of an active DEDB area, use one of the following methods to add the fields:
   • If you use the DBDGEN utility, add one or more FIELD statements under the SEGM statement of the segment that you are altering.
   • If you use DDL, use the ALTER TABLE statement with the INTERNALNAME parameter.
3. If you are replacing the randomizer or adding a Segment Edit/Compression exit routine, assemble and link edit the randomizer and the Segment Edit/Compression exit routine into the IMS SDFSRESL or one of the libraries of the IMS SDFSRESL STEPLIB concatenation.

   If you are using the DEDB Alter utility to add a Segment Edit/Compression exit routine, the Segment Edit/Compression exit routine must be able to handle mixed compressed and non-compressed data in a DEDB database. If data is non-compressed, on read access, it does not expand the non-compressed data, and on write access, it compresses the data and writes out as compressed data. If data is compressed, on read access, it expands the compressed data, and on write access, it compresses the data and writes out as compressed data.

4. If you use the IMS generation utilities, run the DBDGEN utility with the updates to the AREA and FIELD statements to alter the new DEDB DBD definitions for the active DEDB area.
5. If you use the IMS generation utilities, run the ACBGEN utility for all PSBs that reference the changed DEDB DBD definitions to the staging ACBLIB.
   If you are using the IMS catalog, use one the following methods to update it after the DEDB Alter utility finishes:

   • Run both the ACB Maintenance utility and the IMS Catalog Populate utility (DFS3PU00).
   • Run the IMS catalog ACBGEN utility (DFS3UACB), which builds the ACBs and populates the IMS catalog in a single job step.
6. If ACBMGMT=CATALOG is specified in the DFSDFxxx member of the IMS PROCLIB data set, populate the new DEDB DBD definitions to the IMS catalog by using one of the following methods:
   • By using the staging ACBLIB that you created in step 4 as input, run the IMS Catalog Populate utility (DFS3PU00) and use the MANAGEDACBS statement with the STAGE parameter.
   • Use DDL.
7. Allocate one or more shadow DEDB area data sets for an active DEDB area to be altered:
   • Allocate two to six new shadow DEDB area data sets if an active DEDB area is defined as multiple area data sets. The DEDB Alter utility supports six shadow DEDB area data sets, because one shadow image copy data set is required. If you need seven area data sets for multiple area data sets, run the DEDB Create utility to create the seventh area data set after the DEDB Alter utility finishes.
   • You can change from single area data set to multiple area data sets at DEDB Alter processing:
     • Allocate two to six new shadow DEDB area data sets if it is to change to multiple area data sets.
     • The DEDB Alter utility supports six shadow DEDB area data sets, because one shadow image copy data set is required.
   • You can change from multiple area data sets to single area data set at DEDB Alter processing:
     • Allocate one new shadow DEDB area data set if it is to change to single area data set.

   The VSAM control interval size must match the SIZE= parameter on the AREA macro statement or the SIZE PRIMARY parameter on the ALTER TABLESPACE statement for the active DEDB area to be altered in the new DEDB DBD definitions.

   If a DEDB database has a sequential dependent (SDEP) segment defined, the shadow area SDEP portion must be greater than or equal to the active area SDEP portion, and the shadow area CI size must be greater than or equal to the active area CI size.

8. Register the shadow data sets that were allocated in step 7 for an active DEDB area to be altered to DBRC by using the DBRC INIT.ADS command with the SHADOW option.
   One must be registered as a SHADOW IC dataset with DBRC. The shadow area data sets are unavailable until the DEDB Alter utility is run to replace the active area data sets with the shadow area data sets:

   INIT.ADS ADDN(name) ADSN(name) AREA(name) DBD(name) SHADOW

   The ADDN(name) for the data sets’ ddname and ADSN(name) for the data sets’ dsname must be unique for each shadow area data set, and they must be different from those of its associated active area data set.

9. For the active DEDB area to be altered, format the data sets with the updated DEDB area definitions. Use the DEDB Initialization utility (DBFUMIN0) with the SHADOW control statement to format the data sets in the staging ACBLIB.
   After the DEDB Initialization utility runs, these shadow DEDB area data sets remain inaccessible to IMS online system but are marked available in DBRC under the 'SHADOW ADS LIST:'
10. Register one of the shadow area data sets, which was allocated in step 7, as a shadow image copy data set for an active DEDB area to be altered to DBRC. Use the DBRC INIT.ADS command with SHADOW and IC options to register the shadow image copy data set.
    The shadow image copy data set is unavailable until the DEDB Alter utility is run to replace the active DEDB area data sets with the shadow area data sets. The image copy is created by the DEDB Alter utility during execution.

    INIT.ADS ADDN(name) ADSN(name) AREA(name) DBD(name) SHADOW IC

    The ADDN(name) for the shadow image copy data set's ddname and ADSN(name) for the shadow image copy data set's dsname must be different from those of its associated area data set.

11. Format one shadow image copy data set for the active DEDB area to be altered with the updated DEDB area definitions for the DEDB database associated with the active DEDB area to be altered in the staging ACBLIB using the DEDB Initialization utility (DBFUMIN0).

    After the DEDB Initialization utility runs, the shadow image copy data set remains inaccessible to IMS online systems.

    You can format shadow area data sets and shadow image copy data sets for a DEDB area to be altered in one DEDB Initialization utility execution.

    After the DEDB Area Initialization utility completes, the shadow area and shadow image copy data sets are marked as SHADOW AVAIL in the RECON.

12. Run the DEDB Alter utility using the ALTERAREA function to alter an active DEDB area while the DEDB area remains accessible online.

    If you are adding a Segment Edit/Compression exit routine, during DEDB Alter utility execution the new Segment Edit/Compression exit is not invoked for any areas. The Segment Edit/Compression exit routine is not enabled during DEDB Alter processing. Instead, it is enabled for all DEDB areas after successful DEDB Alter utility completion.

DELETE.ADS ADDN(name) AREA(name) DBD(name)