Chapter 8. Codd's Rules for Relational Database Design
In October 1985, E.F. Codd published a series of two articles in the computer industry weekly Computerworld. The first article laid out 12 criteria to which a “fully relational” database should adhere. The second article compared current mainframe products to those 12 rules, producing a flurry of controversy over whether it was important that database management systems (DBMSs) be theoretically rigorous or that they simply work effectively.
If you have read Appendix A
, you will be aware of a product based on the simple network data model called IDMS/R. When Codd rated IDMS/R—which at the time was being marketed as a relational DBMS—it met none (0) of his 12 rules. DB/2, IBM's flagship ...