Location: [CPSC 333] [Assignments] [Clarifications of Instructions for Assignment #1] Operations for a Data Management Subsystem
Question:
What exactly is meant by a set of operations for a ``data management subsystem''?
Answer:
Think of a ``data management subsystem'' as being a part of the system that includes the system's internal data tables (that is, the data that's represented by the ERD), and a set of ``interface functions'' (or ``interface procedures'') The interface functions should be used by the rest of the system to access or modify the data in the tables, and it shouldn't be possible for the rest of the system to view or modify this data except by using these interface functions.
The ``data management subsystem'' shouldn't do anything else - that is, it should only be responsible for maintaining and providing access to the system's stored data.
Thus, you can think of the ``data management subsystem'' (and its operations) as corresponding to the data stores on the system's data flow diagrams, and the services they provide for all the processes that are shown on the DFD.
To answer this part of the first question on the assignment, you should try to list the functions that the above ``interface'' (between the data tables and the rest of the system) would include (and give a very brief description of what each does, if the name you've chosen doesn't make this clear). Try to make sure that your interface is complete enough so that the system really could function correctly, using it - but, try to make this interface as simple as you can, too.