Overview of DDM functions

This topic gives an overview of the types of DDM functions that can be done on a target server.

The following file operations, normally specified in HLL programs, can be done on files at target servers:

• Allocating, opening, or closing one or more files.
• Reading, writing, changing, or deleting records in a file.

The following file and nonfile operations, normally specified in CL programs or by CL commands, can be done on files at the target servers:

• Copying the contents of a file.
• Performing operations on physical or logical file members (such as adding, clearing, or removing members), but only if the target is an iSeries™ server or System/38™.
• Accessing remote files for nondata purposes, such as:
  • Displaying information about one or more files, using commands such as Display File Description (DSPFD) and Display File Field Description (DSPFFD). These commands can display the file attributes of the DDM file on the source system or the file or field attributes of the remote file on the target system.
  • Controlling the locking of files on the target system, using the Allocate Object (ALCOBJ) and Deallocate Object (DLCOBJ) commands.
  • Deleting, renaming, creating, and changing files using the Delete File (DLTF), Rename Object (RNMOBJ), Create Physical File (CRTPF), Create Source Physical File (CRTSRCPF), Create Logical File (CRTLF), Change Physical File (CHGPF), Change Logical File (CHGLF), and Change Source Physical File (CHGSRCPF) commands.
• Accessing remote systems for non-data purposes:
  • Send a CL command to the target system (an iSeries server and a System/38 only) so it can be run there, instead of on the source system (where it might not be useful to run it), using the Submit Remote Command (SBMRMTCMD) command. The SBMRMTCMD command is the method you use to move, save, or restore files on a target server. For example, a Move Object (MOVOBJ) command might be sent to move a database file on the target server. (For typical uses of the SBMRMTCMD command, refer to its description in Use CL and DDS with DDM or refer to the CL topic for a more complete description.)

Various other nonfile-related operations can also be done on the target server.