CA Dynam for VSE User Guide

Controlling Generation Data Sets
Deleting Generation Data Sets
CA Dynam/D will also delete any outdated generations based on the number of
generations defined in the Catalog for this file. If, for any reason, the program
abends, the current generation number remains intact and thus allows the
program to be rerun without any JCL changes. The current generation number
will remain unchanged until the next creation of the file. It is used by CA
Dynam/D to determine which version to access when the file is subsequently
processed as input.
The CA Dynam/D DASD allocation routines will assume that any expired CA
Dynam/D-created file is available for deletion. Generation data sets are always
allocated as permanent files to ensure that they are controlled exclusively by
version.
Generation Data Set Option
You can specify an option on the DLBL to control which file generation is to be
accessed. If you don't specify an option, CA Dynam/D will read the most
current file. (To follow the syntax rules defined for CA Dynam/D option codes,
enclose the file generation option in parentheses.) With this option, you can
request access to a version by specifying any one of the following about the
files:
• Generational number
• Absolute generation number
• Relative generation number
Generational Numbers
The generational number is recorded in the file ID of the disk VTOC for each
version. To request a version by its generational number, include that number
as an option in the file ID field of the DLBL statement. For example, to request
the sixth version of a file (defined as G#06 in the VTOC entry for that file), use
the following option code:
// DLBL FILE,'DISK.FILE(G#06)'
4–22 User Guide