After you identify the initial procedures on the DLG, you need to decompose these into client and server procedures (called client-to-server mapping). This mapping can take several forms, as the following bullets show. The last three bullets correspond to a style of client/server applications called the distributed process style.
This mapping assumes that all processing is performed on the client, with data stored remotely on a server or locally on a client, and accessed directly from the client procedure using a DBMS to obtain data from the server. The advantage of this mapping is that all the processing is in one place and maintenance is easier.
With this mapping, the client and server procedures are seen as closely coupled pairs. The server procedure is developed specifically to serve the needs of the client. The client procedure is developed specifically to receive the data provided by the server procedure.
You can conveniently define this mapping as two procedure steps of the same procedure. The client procedure is the first step so that other client procedures can flow to it. Using two procedure steps of the same procedure, however, keeps other client procedures from accessing the server procedure step. The flow can go only to the first step of the multiple-step procedure.
This mapping implies a multifunctional client procedure being serviced by many server procedures. This makes the server procedures relatively simple and individually easy to maintain. However, the client procedure may become more complex and the DLG is more complicated.
You may find it more convenient to define this group of procedures as procedure steps of the same procedure. The client procedure is the first step and the server procedures are the following steps. With such a definition, other client procedures cannot access the server procedure steps.
In this mapping, the functionality of each server procedure is implemented to be reusable by many client procedures. Reusability in this case may result in complex server procedures as well as complex client procedures. On the DLG, each server must be a procedure (not a procedure step). Reusability might be better achieved by means of reusable action blocks.
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