The table below recommends the type of device allocation to use based on the needs of your program.
| When... | Choose: |
|---|---|
| You need data to be available for the duration of your program | JCL |
| You need to know that the program has access to all data before execution begins | JCL |
| Your data requirements are constant for all program conditions | JCL |
| You need data only in certain paths of program processing | Dynamic allocation |
| Your program can wait or fail if the data is not available when you issue the DYNALLOC macro | Dynamic allocation |
| Your program is a long-running job or server that could cause contention for system resources | Dynamic allocation |