By using distributed relational database files, you can more easily expand the configuration of your iSeries™ servers.
Before the DB2® Multisystem, if you wanted to go from one system to two systems, you had several database problems to solve. If you moved one-half of your users to a new system, you might also want to move one-half of your data to that new system. This then forces you to rewrite all of your database-related applications, because the applications must know where the data resides. After rewriting the applications, you must use some remote access, such as Distributed Relational Database Architecture™ (DRDA®) or distributed data management (DDM), to access the files across systems. Otherwise, some data replication function would be used. If you did do this, then multiple copies of the data would exist, more storage would be used, and the systems would also do the work of keeping the multiple copies of the files at concurrent levels.
With DB2 Multisystem, the process of adding new systems to your configuration is greatly simplified. The database files are partitioned across the systems. Then the applications are moved to the new system. The applications are unchanged; you do not need to make any programming changes to your applications. Your users can now run on the new system and immediately have access to the same data. If more growth is needed later, you can redistribute the files across the new node group that includes the additional systems.