Databases supported by DCCTL
The DCCTL configuration of IMS supports and is a compatible communications front end for database and dependent region combinations.
The following database and dependent region combinations are compatible communications front end for a DCCTL configuration of IMS:
- GSAM databases for BMP regions
- Db2 for z/OS® databases
for:
- JMP, JBP, BMP, MPP, and IFP regions through the External Subsystem Attach Facility (ESAF)
- JMP and JBP regions through the DB2® Recoverable Resource Services attachment facility (RRSAF)
- Fast Path databases
- Full-function databases
- The IMS catalog, a HALDB full-function system database
With GSAM databases, DCCTL uses sequential, non-IMS data sets with a BMP. Application programs can also issue symbolic checkpoint (CHKP) and extended restart (XRST) calls against a GSAM data set using the I⁄O PCB. The ability to issue CHKP and XRST calls allows data set repositioning.
When DCCTL accesses Db2 for z/OS databases through the ESAF or RRSAF interfaces, the control region initiates contact with other subsystems. The other subsystems that DCCTL can access are defined in a subsystem member (SSM) of the IMS.PROCLIB data set that you provide. The subsystem definition contains the information DCCTL uses to communicate with the other subsystems.
- For more information about accessing external subsystems from IMS, see Accessing external systems from within IMS.
- For more information about RRSAF, see DB2 for z/OS Application Programming and SQL Guide.
DCCTL handles transaction management for online IMS applications that need to access external subsystems.