Database Reference
In-Depth Information
•
In constructing the RAL and RL, it is sometimes useful to use the
RL to refine the RAL and vice versa. In particular, once you have
identified all the (mandatory) relationships, you may use this along
with the principles outlined in section 3.5.4 to refine the RAL.
•
Remember, the model of Figure
3-4b
, RAL of Figure
3-13
, and the
RL of Figure
3-14
do not represent a comprehensive coverage of
the database requirements of a manufacturing firm; neither are
they intended to be. Rather, they serve as useful illustrations.
Figure 3-13.
Partial Relation-Attributes List for a Manufacturing Firm's Database
