Shared Storage

The term shared storage, as it pertains to this discussion, refers to any space data that is accessed from two or more threads. This definition includes any storage directly accessible down to its individual bytes, and can include the following classes of storage:

MI space objects
Primary associated spaces of other MI objects
POSIX shared memory segments
Implicit process spaces: Automatic storage, static storage, and activation-based heap storage
Teraspace

The system considers these spaces, regardless of the longevity of their existence, as shared storage when accessed by multiple threads capable of concurrent processing.