The implementation of DRDA® support on the iSeries™ server uses Distributed Data Management (DDM) conversations for communications. Because of this, you can use DDM in conjunction with distributed relational database processing.
You can use DDM to submit remote commands to an application server (AS), copy tables from one iSeries server to another, and process nondistributed relational database work on another server.
With distributed relational database, information the application requester (AR) needs to connect to a database is provided in the relational database directory. When you use DDM, you must create a separate DDM file for each file you want to work with on the application server (AS). The DDM file is used by the application on the application requester (AR) to identify a remote file on the application server (AS) and the communications path to the application server (AS).
As of V5R2, you can also create DDM files with a reference to an RDB directory entry. Some database administration tasks discussed in Manage a distributed relational database use DDM to access remote files. A DDM file is created using the Create Distributed Data Management File (CRTDDMF) command. You can create a DDM file before the file and communication path named in the file have been created. However, the file named in the DDM file and the communications information must be created before the DDM file is used by an application.
The following example shows one way a DDM file can be created:
CRTDDMF FILE (TEST/KC105TST) RMTLOCNAME(KC105) RMTFILE(SPIFFY/INVENT)
If the DDM file access in the example is to be over TCP/IP, you must specify *IP in the second element of the RMTLOCNAME parameter.
This command creates a DDM file named KC105TST and stores it in the TEST library on the application requester (AR). This DDM file uses the remote location KC105 to access a remote file named INVENT stored in the SPIFFY library on the target iSeries server.
You can use options on the Work with DDM Files display to change, delete, display or create DDM files.