You can request that a concatenated group created through DYNALLOC
be assigned the permanently concatenated attribute. A group with the
permanently concatenated attribute has the following characteristics:
- The group cannot be dynamically deconcatenated into its member
data sets.
- Except for the first data set in the concatenation, the data sets
in the concatenation are no longer associated with their original
ddnames. Instead, all data sets in the concatenation are associated
with the ddname of the first data set in the concatenated group.
- If a permanently concatenated group is dynamically concatenated
with other data sets to form a new non-permanently concatenated group,
the permanently concatenated group remains intact if the new group
is dynamically deconcatenated.
- If the group is not a system-defined permanently concatenated
group, it is automatically assigned the permanently allocated attribute.
Note: To dynamically release a non-system-defined permanently
concatenated group, you specify the ddname, not the dsname, in the
unallocation request.
A concatenated group defined through JCL is automatically assigned
the permanently concatenated attribute, as is a concatenated group
defined by the system through JCL or DYNALLOC. A GDG ALL request and
a request for a VSAM data set that spans device types are examples
of the latter situation.