Example: Processing multiple requests for remote files with DDM

This example shows a System/36 server system. The SDDM is shown handling requests for two files from two programs in different jobs, and two TDDMs are handling the requests on the server system (one TDDM for each requesting program). Although program B is accessing two files on the server system, only one TDDM is created if all the associated DDM files specify the same remote location information to identify the server system.

Both programs A and B are sharing FILEA. However, because these programs are shown to be in separate jobs, they cannot share the same open data path (ODP) to FILEA. If they were in the same job, programs A and B can share both the ODP on the client system and the remote file. When multiple programs within the same job are accessing a remote file at the same time (by using one TDDM for each program), the rules for file sharing are the same for remote files as for local files. These rules are based on how the SHARE parameter is specified on the Create DDM File (CRTDDMF), the Override with Database File (OVRDBF), and the Change DDM File (CHGDDMF) commands.