CA Dynam for VSE User Guide

Using CA Dynam/T
When the DYNCAT SCRATCH command is performed to scratch eligible data
set versions, if a data set has AS-OF-DATE cycles specified, as many versions
will be retained as have AS-OF-DATES different from the next most current
version.
Days Since Last Access Retention
Each time you access a version, CA Dynam updates the last access date field
in the Catalog. This value is compared with the current date. If the last access
date plus the NOACC value (number of days that version is to be retained after
last access) is less than the current date, the version is eligible for scratch
under this retention option.
Modifying Retention Characteristics
The DYNCAT ALTER command enables you to modify the existing retention
characteristics of a data set.
For example, this ALTER command assures that a particular version will not be
scratched until December 31, 2020.
ALTER 'PR MASTER' VERSION=1 EXPDATE=12/31/2020
The expiration date of version 1 of the data set is changed to December 31,
2020. DYNCAT accepts American and European date formats. For more
information about acceptable dates, see the DYNCAT ALTER command.
Scratching Eligible Data Set Versions
The SCRATCH command of the batch program DYNCAT analyzes each data set
and scratches eligible versions. A version remains a protected member of the
data set until the SCRATCH command is run, even if its expiration date has
passed. This lets you control the process by which tapes are returned to the
scratch pool.
However, a version of a data set becomes a scratch tape available for
immediate use if the following conditions are met:
• You run the DYNCAT DELETE command.
For example:
DELETE 'PR MASTER' VERSION=1
or
DELETE 'PR MASTER' VOLSER=(845)
• A version of a released WORK data set becomes a scratch.
2–10 User Guide