Conceptual Overview - Database Design for Mere Mortals - page 64

1. Define a mission statement and mission objectives for the database. The mission
statement defines the purpose of the database, and the mission objectives define
the tasks that are to be performed by users against the data in the database.
2. Analyze the current database. You identify your organization's data requirements
by reviewing the way your organization currently collects and presents its data and
by conducting interviews with users and management to determine how they use
the database on a daily basis.
3. Create the data structures. You establish tables by identifying the subjects that the
database will track. Next, you associate each table with fields that represent dis-
tinct characteristics of the table's subject, and you designate a particular field (or
group of fields) as the primary key. You then establish field specifications for
every field in the table.
4. Determine and establish table relationships. You identify relationships that exist
between the tables in the database and establish the logical connection for each re-
lationship using primary keys and foreign keys or by using linking tables. Then
you set the appropriate characteristics for each relationship.
5. Determine and define business rules. You conduct interviews with users and man-
agement to identify constraints that must be imposed upon the data in the database.
The manner in which your organization views and uses its data typically determ-
ines the types of constraints you must impose on the database. You then declare
these constraints as business rules, and they will serve to establish various levels of
data integrity.
6. Determine and establish views. You interview users and management to identify
the various ways they work with the data in the database. When your interviews
are complete, you establish views as appropriate. You define each view using the
appropriate tables and fields, and you establish criteria for those views that must
display a limited or finite set of records.
7. Review data integrity. This phase involves four steps. First, you review each table
to ensure that it meets proper design criteria. Second, you review and check all
field specifications. Third, you test the validity of each relationship. Fourth, you
review and confirm the business rules.
Review Questions
1 . Why is it important to complete the design process thoroughly?
2 . True or False: The level of structural integrity is in direct proportion to how thor-
oughly you follow the design process.