CS 4400 Chapter Notes - Chapter 14: Multivalued Dependency, Unique Key, Fifth Normal Form
24 Dec 2017
School
Department
Course
Professor
Document Summary
Basics of functional dependencies and normalization for relational databases. Formal concepts of functional dependencies and normal forms. Semantics of the relational attributes must be clear. Each tuple should represent one entity or relationship instance. Attributes of different relations shouldn"t be mixed within the same relation. Only foreign keys should be used to refer to other entities. Entity and relationship attributes should be kept apart as much as possible. A change to one instance can impact the rest. Guideline for redundant information in tuples and update anomalies. Design a schema that doesn"t suffer from the insertion, deletion and update anomalies. Tuples should have as little null values as possible. Attributes that are often null could be put in separate relations. Avoid generation of spurious tuples at all costs. Relations should be designed to satisfy the lossless join condition. No fake tuples should be made by doing a natural join of any.
