Transcript Database Design Overview and Principles

Database Design
Overview and Principles
Why Design?
A well designed relational database
maintains data integrity and allows
you to access any data and compare
it to any other data.
 A poorly designed relational database
can make it impossible to retrieve or
enter needed information
 Taking the time to carefully design a
database is essential
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Advantages of Methodology
It gives you the skills you need to to
design a sound database
 Provides an organized set of
techniques and procedures
 Helps reduce missteps
 Makes design easier and faster
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Objectives of Good Design
A database that supports required
and ad hoc queries
 Proper and efficient table structure
 Data integrity at all levels
 Support of business rules
 Scalable: supports future growth
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Design Methods
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Traditional database design methods
incorporate 3 phases
Requirements analysis
 Data modeling
 Normalization
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Note on Normalization
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“Normalization is the process of
decomposing large tables into smaller ones
in order to eliminate redundant data and
duplicate data and to avoid problems with
inserting, updating, or deleting data.” page
36
The author incorporates Normalization into
his method without treating it specifically.
We will cover it briefly because you will be
expected to know what is meant by Normal
forms, etc.
Note:
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This PowerPoint is based on Chapter
Two of Database Design For mere
Mortals 2nd Edition by Michael J.
Hernandez