Database Reference
In-Depth Information
Another part of the analysis involves conducting interviews with users and management to
identify how they interact with the database on a daily basis. As the database developer,
you ask users how they work with the database and what their information requirements
are at the current time. You then interview management personnel and ask them about the
information they currently receive and their perception of the overall information require-
ments for the organization. These interviews are an important component of your analysis
becausethequestionsyouask(ordon'task)willhaveagreatimpactonyourfinaldatabase
structure. You must conduct full and complete interviews if you are to design a database
that truly meets your organization's information needs.
Next,youusetheinformationyou'vegatheredfromtheanalysisandtheinterviewstocom-
pile an initial list of fields. You then refine this list by removing all calculated fields and
placing them on their own list—you'll use these calculated fields later in the design pro-
cess. The refined list constitutes your organization's fundamental data requirements and
provides a starting point for the design of a new database. (As you know, nothing is ever
truly final. Rest assured that you'll extend and refine this field list further as you develop
your design.)
Once your initial field list is complete, you send it to your users and management for a
brief review and possible refinement. You encourage feedback and take their suggestions
for modifications into consideration. If you think the suggestions are reasonable and well
supported, you make the appropriate modifications, record the list in its current state, and
move on to the next phase.
Creating the Data Structures
Creating the data structures for the database is the third phase in the database design pro-
cess. You define tables and fields, establish keys, and define field specifications for every
field.
Tablesarethefirststructuresyoudefineinthedatabase.Youdeterminethevarioussubjects
thatthetableswillrepresentfromthemissionobjectivesyouwroteduringthefirstphaseof
the design process and the data requirements you gathered during the second phase. Then
you establish these subjects as tables and associate them with fields from the field list you
compiled during the second phase of the design process. After you've completed this task,
you review each table to ensure that it represents only one subject and that it does not con-
tain duplicate fields.
Now you go on to review the fields within each table. You refine all multipart or multival-
ued fields in the table so that they each store only a single value, and you move or delete
fields that do not represent distinct characteristics of the subject the table represents. When
you complete this review, you then review and refine the table structures. This involves
