The persistence attribute of a structure is affected both by how you define your structure disposition and the disposition of the connections to the structure.

The structure disposition (STRDISP) determines whether or not the structure remains allocated when there are no active or failed-persistent connections to the structure. A structure disposition of KEEP indicates that when there are no active or failed-persistent connections to the structure, the structure remains allocated. For example, if data in the structure needs to be kept permanently in the coupling facility, you should specify a disposition of KEEP. A structure that remains allocated when there are no active or failed-persistent connections is called a persistent structure. The operator or an authorized program can use the SETXCF FORCE command or the IXLFORCE macro to delete a persistent structure in some instances. On systems with OW33615 installed or which are at OS/390® Release 9 or higher, when connectivity to a coupling facility is lost by all systems and the system receives a request to allocate and connect to a structure in that coupling facility, the system will FORCE all failed-persistent connectors to the structure as well as the structure itself. This allows the connector to connect successfully to a new instance of the structure, so that it can perform whatever recovery actions are necessary to ensure data consistency and then begin to provide service making use of the newly allocated structure instance. See Deleting Persistent Structures.

A structure with a disposition of KEEP can also be deleted if the last remaining connector to the structure disconnects with REASON=DELETESTR on the IXLDISC request. See Disconnection to Delete the Structure.

A structure disposition of DELETE indicates that when there are no active or failed-persistent connections to the structure, the structure is deallocated. However, if there are any active or failed-persistent connections to the structure, the structure remains allocated.

Note that you can determine the persistence attribute of both a structure and a connection with the IXCQUERY macro.