The CONTROL parameter is used to control parallel execution of jobs.
If a job requires a resource in exclusive state, it cannot share usage of that resource with another job (that is, the jobs cannot run in parallel). For example:
If JOBA requires exclusive control of a resource that is already in use by a different job, JOBA must wait until the other job frees the resource regardless of whether the other job is using the resource in shared or exclusive state.
If JOBA already has exclusive control of a resource, any job requiring that resource must wait until JOBA frees the resource, regardless of whether the job requires the resource in shared or exclusive state.
If a job requires a resource in shared state, that job can run in parallel with other jobs requiring the same resource in shared state. For example:
If JOBA requires shared control of a resource that is already in shared use by different jobs, JOBA can use that resource at the same time.
If JOBA already has shared control of a resource, any job requiring that same resource in shared state can use that resource at the same time.
However:
If JOBA requires shared control of a resource that is already in exclusive use by a different job, JOBA must wait until the other job frees the resource.
If JOBA already has shared control of a resource, any job requiring that same resource in exclusive state must wait until JOBA frees the resource.
