Database Reference
In-Depth Information
What you understand now is that data views relate to the real-world information
on one side and to the completed database system on the other side. The objective
of a database development project is the implementation of a database system that
matches with the information requirements. Now you see the connection and role
of data views in the development process.
VIEW INTEGRATION
Data views offer a useful link from real-world information requirements to the fin-
ished database system. You can assemble the data views from the side of real-world
information, consolidate them, and derive the proposed database system. How are
these data views assembled? What is the process? The combining of the data views
results in a consolidated data model for the proposed database system. Let us now
discuss this topic.
We have established the connection between data views and data model. The
data model is derived from the data views. Go back to the real-world information.
This, as we have seen, is a collection of individual user views. You get the resultant
data model by combining the separate user views. How can you accomplish this and
produce the entire data model? Analysts adopt one of two distinct approaches
depending on the circumstances and skills of the data modelers. Here are the two
approaches or methods:
Merge individual user views.
You take all the individual user views, merge these
user views, and then create the complete data model from the complete set of
merged data views.
Integrate partial data models.
You create a partial data model with standard build-
ing blocks for each user view and then integrate these partial data models into the
complete data model.
Figure 5-14 illustrates the two approaches showing three user views. The princi-
ple can be extended to any number of data views.
Merging Individual User Views
This approach for creating the consolidated data model by merging individual user
views generally consists of the following major tasks. Amend and adapt this list to
suit your database project.
1. Take each user view and group the data elements by business objects.
2. Within each user view, identify the relationships among the data groups.
3. Take three or four user views at a time and combine the data groups elimi-
nating duplicate elements.
4. For each such combination, mark the relationships among the data groups.
5. Repeat tasks 3 and 4 until all user views are combined.
6. Separate out objects and their characteristics.
7. Establish relationships among objects.
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