Normalization Notes - NOTES on NORMALIZATION: 1st Normal...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
NOTES on NORMALIZATION: 1 st Normal form: Definition: Must be a relation. Translation : Must not have any repeating groups of attributes—i.e., attributes or groups of attributes that have multiple values for one instance of the entity. Method(1): “Back to the ERD method”—For any multivalued attribute (or group of attributes), add an entity to the ERD and model the relationship between new entity and existing entity as one-many or many-many. Examine other attributes to determine if attributes apply to multivalued attribute or stay in original structure. For example, Student with multiple majors would become Student and Major entities with many to many relationship (Student has many Majors and a Major can be had by many Students). Method (2): In some cases, multivalued attributes can be divided into two or more separate attributes. (e.g., HomePhone, WorkPhone, etc.) This should be considered carefully since it can cause problems in retrieving data. (e.g., Major1 and Major2 would require searching two fields to
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/21/2011 for the course CGS 2545 taught by Professor Markllewellyn during the Summer '10 term at University of Central Florida.

Page1 / 2

Normalization Notes - NOTES on NORMALIZATION: 1st Normal...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online