Functional Dependency Closure Explained for Database Design
What Is Meant by the Closure of a Set of Functional Dependencies?
A functional dependency is a one-way dependency between two attributes at any given time. For a unique attribute
of value A there is one value of the attribute B associated with it through the relation. Even if the values for the attribute change, there is only one, as described by Harrington(2009). A functional dependency, as explained by Elmasri & Navathe (2015), is a constraint between two sets of attributes from the database.
Elmasri & Navathe (2015) defined F as a set of functional dependencies that are specified on relation schema R. They go on to describe a closure F+ of F as a set of all functional dependencies that could be inferred from F.
References
Elmasri, R., Navathe, S. B. (2015). Fundamentals of Database Systems, 7th Edition [VitalSource Bookshelf version]. Retrieved from https://bookshelf.vitalsource.com/books/9781323139899
Harrington, J. L. (2009). Relational Database Design and Implementation. : Elsevier Science. Retrieved from http://www.ebrary.com
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- Cursors in Embedded SQL: Usage, Power, and Performance
- Object vs. Relational Databases: Key Design Differences
- Mapping EER Model Constructs to Relations in Your Database
- Attribute and Relationship Inheritance in EER Diagrams
- SQL Join Types: Inner vs. Outer Join Operations Explained
- Demystifying SQL Retrieval Queries A Step-by-Step Breakdown
- Database Anomalies: Insertion, Deletion, and Modification
- Functional Dependency Closure Explained for Database Design
- Variable-Length Records and Separator Characters Explained
- Essential Measures for Preventing SQL Injection Attacks
- Disaster Recovery from Catastrophic Database Failures
- Types of Database Failures in DBMS: Transaction, System, Media