The Free On-line Dictionary of Computing (30 December 2018):

Distributed Data Management

    (DDM) An IBM data protocol
   architecture for data management services across distributed
   systems in an SNA environment.

   DDM provides a common data management language for data
   interchange among different IBM system platforms.

   Products supporting DDM include AS/400, System/36,
   System/38 and CICS/DDM.

   On the AS/400, 	DDM controls remote file processing.
   DDM enables application programs running on one AS/400
   system to access data files stored on another system
   supporting DDM. Similarly, other systems that have DDM can
   access files in the database of the local AS/400 system.
   DDM makes it easier to distribute file processing between two
   or more systems.

   OS/400 Distributed Data Management V3R6 Reference

(http://as400bks.rochester.ibm.com/cgi-bin/bookmgr/bookmgr.cmd/BOOKS/QBJALH00/CCONTENTS).

   (1999-04-26)