Databases Reference
In-Depth Information
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Provides a data dictionary.
The dictionary should capture definitions
for the relational database and related objects and should provide a
cross-reference from the logical data model to relational constructs.
•
Bases the methodology on a logical data model.
Designers will not au-
tomatically build logical data models first. Therefore, a logical data
model must be made as a prerequisite, if only by using terminology in
the relational design steps that demands the application of logical
data modeling concepts.
•
Provides for database design reviews.
Checkpoints must be established
throughout the design process that allow or require designers to solic-
it opinions and insights from other people. Design review sessions
should be supported with design documentation produced by the
data dictionary or relational DBMS, and standard forms (preferably
computer-based) containing additional relevant design information
must be used.
•
Includes both structural and integrity considerations in the relational da-
tabase implementation.
Business rules should be enforced as part of an
integrated data-driven process rather than by individual applications
or users. Standards for enforcing these rules must be defined in a con-
trolled and integrated fashion within the environment.
•
Uses a database diagramming technique to illustrate the relational data-
base design.
Similarities in diagramming constructs should be used to
convey similarities between the logical data model and the relational
database design. In addition, the use of tuning techniques, such as in-
dexes, hashed access, and duplicate data, should be conveyed in the
relational diagram.
BENEFITS AND APPLICABILITY OF A RELATIONAL DATABASE DESIGN
METHODOLOGY
A relational database design methodology provides several benefits. It
promotes early usability of a new relational DBMS or related product, espe-
cially by encouraging development of prototypes. It removes fear and
doubt in the minds of first-time designers. It communicates common and
proven approaches for solving functional and performance challenges. It
promotes consistent documentation and effective communication of
design alternatives and justifications.
Moreover, a relational database design methodology is applicable under
many circumstances. A few examples are:
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Developing preliminary or prototype databases.
In this instance, the de-
signer will probably need only to translate the logical data model and
choose access approaches. Many technical and product-specific steps
can be omitted.
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