Dynamic allocation provides some controls designed specifically for the interactive environment. The following features help to avoid tying up resources that are not being used, or allow you to reuse resources that have already been allocated.
| Feature | Described in topic | Purpose |
|---|---|---|
| In-use attribute | In-use attribute | Determines whether a data set is eligible to be used by another dynamic allocation, or determines whether a data set or z/OS® UNIX file can be deallocated if the control limit is reached. |
| Control limit | Control limit | Limits the number of data sets that can be allocated but not in use. |
| Permanently allocated attribute | Permanently allocated attribute | Prevents the system from automatically deallocating a data set to meet the control limit. |
| Convertible attribute | Convertible attribute | Allows dynamic allocation to change certain parameters of an existing allocation to match a dynamic allocation request. |
| Ddname allocation | Using ddname allocation | Allows you to reuse a previously allocated data set that is not in use. |