Additional DDM concepts

Most users of DDM will not need the information in the remainder of these topics; it is intended primarily for experienced programmers who need to know more about DDM.

Described are conceptual details and examples about:

• Program start requests, which start the TDDMs (target jobs)
• Open data paths (ODPs), used to access the files
• Remote location information
• DDM conversations, established for source and target communications
• Source and target jobs
• I/O operations within a job

• iSeries server as the source server for DDM
  When an application program or user in a source server job first refers to a DDM file, several actions occur as part of processing the request on the source server.
• iSeries server as the target server for DDM
  The iSeries™ target DDM (or TDDM) is actually a job that runs a DDM-related target server program. It is started when the source server sends a program start request (an SDDM).
• DDM-related jobs and DDM conversations
  This topic provides additional information about activation groups, source server jobs, target server jobs, and the DDM conversations used by those jobs.