FORMAT of SYSTRK files

Products

• IDMS

Issue/Introduction

Considering the implementation of change tracking.

CV is shut down once a week and the intention would be to reformat the SYSTRK* files after every successful shutdown in order to avoid running into space issues on the SYSTRK* files. Is this a good way to go? Or is there already an internal mechanism at CV startup that takes care of the SYSTRK* files?

Environment

Release: All supported releases.

Resolution

The size of the SYSTRK files is primarily determined by the size of the DMCL, in other words, the number of areas and files defined within the DMCL. Sizing considerations are described at FORMAT.

The file does not accumulate images of all CV executions since the creation of the file. It works much like a PDS in that it keeps the previous image and builds an image for the new CV execution. The 'old' image is then reused during a future execution. Starting to vary areas using a permanent option can increase the size requirement but it should not be too significant of an increase. If the size of the DMCL is changed, then the SYSTRK files must be resized.

Reformatting the file continually would result in the loss of any permanent area status values set during a previous execution of the CV although it would still provide the recovery aspects of the SYSTRK file.