Call Attachment Facility
With the CAF, your application program can establish and control its own connection to DB2. Programs that run in MVS batch, TSO foreground, and TSO background can use CAF. It is also possible for IMS batch applications to access DB2 databases through CAF, though that method does not coordinate the commitment of work between the IMS and DB2 systems. We highly recommend that you use the DB2 DL/I batch support for IMS batch applications.
Programs using CAF can
Access DB2 from address spaces where there is no TSO, CICS, or IMS.
Access the IFI.
Access DB2 from multiple tasks within an address space.
Control the connection to DB2 explicitly.
Connect to DB2 implicitly using a default subsystem ID and plan name.