What Is CA IDMS DDS?

This section describes CA IDMS DDS and the facilities for generating and operating a CA IDMS DDS network.

Each system is a node

CA IDMS DDS is a system that establishes and maintains communication between nodes in a distributed data processing network. Each node in the network is a CA IDMS/DC system or a CA IDMS UCF system. Each node can be generated to provide the services required by a particular group of applications or a wide range of different applications.

Note: The term node, when used in this manual, refers to a CA IDMS DDS node (a CA IDMS/DC system or a CA IDMS UCF system), and should not be confused with a VTAM node or an SNA node.

Using CA IDMS DDS, an organization can realize the benefits of both centralized and decentralized data processing. Nodes can be located at the same site or at remote sites, and each node can control one or more CA IDMS databases. Application programs can access any database in the network, and the network is designed so the location of all databases is transparent to application programs.

Host and target nodes

Under CA IDMS DDS, a single node accepts application requests for database services and either processes those requests directly by accessing a database under its controls or passes the requests to the node that controls the appropriate database. Once the requesting node (the host node) routes a request to another node (the target node), the target node performs the requested service and returns the results to the host. The host then returns the results to the application. The process of locating the appropriate database and routing the requests to the controlling node is transparent to the requesting application.

Distribute or centralize data

The data available to applications executing within the network can be distributed among databases controlled by several different nodes; alternatively, all data can be stored centrally in a single database, where the controlling node processes all application requests originating at other nodes. Additionally, using CA IDMS UCF, the network can be designed to permit online transactions originating at one node to be executed at a remote node.

CA IDMS DDS is flexible

CA IDMS DDS permits flexibility in designing a distributed database network. Any number of DC/UCF systems can participate in the network; each node can be located at a remote site, or several nodes can be located at a single site. Depending on the location of the individual nodes, communication between nodes takes place by way of the SVC (Supervisor Call) Routine or a telecommunications line.