SQL and Relational Theory, 2nd Edition

OBJECTIVES OF THE RELATIONAL MODEL

For purposes of reference if nothing else, it seems appropriate in this appendix to document Codd’s own stated objectives in introducing his relational model. The following list is based on one he gave in his paper “Recent Investigations into Relational Data Base Systems” (an invited paper to the 1974 IFIP Congress), but I’ve edited it just slightly here:

1. To provide a high degree of data independence

2. To provide a community view of the data of spartan simplicity, so that a wide variety of users in an enterprise, ranging from the most computer naïve to the most computer sophisticated, can interact with a common model (while not prohibiting superimposed user views for specialized purposes)

3. To simplify the potentially formidable job of the DBA

4. To introduce a theoretical foundation, albeit modest, into database management (a field sadly lacking in solid principles and guidelines)

5. To merge the fact retrieval and file management fields in preparation for the addition at a later time of inferential services in the commercial world

6. To lift database application programming to a new level—a level in which sets (and more specifically relations) are treated as operands instead of being processed element by element

I’ll leave it to you to judge to what extent you think the relational model meets these objectives. Myself, I think it does pretty well.