|
Index - Major Sections
Home
**InHCc HMIS**
Site Map
Health Economic and Reform
Benefits
Discussion
Data and Data
Analysis
Health Management
Product and Services
References
Team
_______________
Index - Same Level Subject
Index - Child Subjects
| |
The value in data, is not in the data but in
the relationship it has to other data.
Introduction
The whole purpose of a database is the representation of the physical
world. The accuracy of the representation depends on the design of the
database.
Design of the Relational Database
Normalization Forms
1st Normal
2nd Normal
3rd Normal
4th Normal
Indexes
Primary Key
Foreign Key
Advantages of A Relational Database
The advance of using a relational database with "unstructured"
research data is that relational databases are very flexible. Data can be
placed in tables that can be largely independent of the other "table of
data." You can add, delete (to a certain degree), or change data in a
table without affecting the data in other tables.
Research
The value in data, is not in the data but in the relationship it has to other
data.
Relationships
Domains and constraints cannot be determined in advance of the creation of
the database for research. It is the research function to determine these
relations.
It is the research that determines the patterns or structure within this
data.
Therefore it may not be possible to "normalize" the database if
the relationships or not known. As structure is imposed on the data, the
database becomes harder to manage.
Null Values (the effect on research)
If logical database design requires a table with several columns that
allow null values, it may be more efficient to consider placing these
columns in another table linked to the primary table.
Issues
In a relation database it is assumed that as the "state" of the
real world changes, so does the current relation state. In addition it is
assumed that the schema R is relatively static (Elmasri-Navathe, pg 140).
However, this may not be true for "real life." It is in fact the
goal of public health to change this schema and the domain of
values.
|