What are the steps to increase DDLDCLOG size

Products

• IDMS
• IDMS - Database

Issue/Introduction

What are the steps to increase the size of the IDMS log area DDLDCLOG?

Environment

Release: All supported releases

Resolution

LOOK DMCL or DCMT D AREA SYSTEM.DDLDCLOG ALL will show the current page range, page size, DSName for the Log area.

Typically all SYSTEM Segments are defined in Page Group 0.  SYSTEM.DDLDCLOG should be Page Group 0.

To increase the page range you should do a LOOK DMCL and see if you have page numbers unused by other areas in page group 0 that are adjacent to this page range on the low or high end so you can increase the number of pages. 

If that does not give you the number of pages you want, you may need to select an entirely different page range using page numbers not already used in page group 0. 

In the case of the SYSTEM.DDLDCLOG area, there is no need to Unload/Reload it. 

Run the ARCHIVE LOG utility just prior to implementing your new larger area after shutting down the CV. 

Make the change to the AREA definition specifying the new larger page range, generate punch and link your DMCL, rename the existing dataset with .OLD, allocate the new file using the DSName currently used, FORMAT FILE SYSTEM.DCLOG using the updated DMCL and bring the CV up with the updated DMCL and the new larger DCLOG. 

Note: 

The ALTER AREA in OCF/BCF needs to be done in two steps. 

The first ALTER will just change the MAXIMUM SPACE specification. 

Then you can make the page range change. 

Example. My SYSTEM.DDLDCLOG area currently displays with these specifications: 

*+ PRIMARY SPACE 4000 PAGES FROM PAGE 30001 

*+ MAXIMUM SPACE 4000 PAGES 

if I want to double the size of this area (I checked my DMCL and pages 34001 through 38000 are not used by any other area in page group 0) so I would make the AREA change like this: 

ALTER AREA SYSTEM.DDLDCLOG 

MAXIMUM SPACE 8000 PAGES;

then the second statement would be: 

ALTER AREA SYSTEM.DDLDCLOG 

PRIMARY SPACE 8000 PAGES FROM PAGE 30001; 

then you rename the existing DMCL load module in your DBA.LOADLIB in case you need to go back for any reason, generate punch and link the DMCL with this change, shutdown, ARCHIVE LOG (using the old DMCL), allocate and FORMAT your new 8000 block DCLOG dataset (using the NEW DMCL) and bring CV up with the new DMCL and log file.

Additional Information

IDMS Database Administration