Fds in relationships and teaches relationship, Database Management System

FDs in Relationships:

 Enrols Relationship: None as it is many to many

Teaches Relationship: Course code → Instructor

Instructor → Course code

The next question is:  How do we recognize the functional dependence in a database model?

Functional dependencies occur from the nature of the actual world that the database models. Often A and B are facts about an entity where A may be some identifier for the entity and B some characteristic. Functional dependencies cannot be automatically determined by studying one or more cases of a database. They can be determined only by a careful study of the actual world and a clear understanding of what every attribute means.

 There are no thumb rules for determining FDs.

Functional dependence is an vital concept and a large body of formal theory has been developed about it.

 

Posted Date: 3/7/2013 1:54:10 AM | Location : United States







Related Discussions:- Fds in relationships and teaches relationship, Assignment Help, Ask Question on Fds in relationships and teaches relationship, Get Answer, Expert's Help, Fds in relationships and teaches relationship Discussions

Write discussion on Fds in relationships and teaches relationship
Your posts are moderated
Related Questions
what is cascading rollback

(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg

Define blocks? The database system resides eternally on non-volatile storage, and is into fixed-length storage units known as blocks.

Problem: (a) Data mining is one of the best ways to analyse data and using software techniques, hidden and unexpected patterns and relationships in sets of data can be extrac

Explain query execution plan? - Optimizer available in SQL Server optimizes code to be effectively executed. - A query execution plan demonstrates how this optimizer would r


What is a hash index? A hash index organizes the search keys, with their associated pointers, into a hash file structure.

How can you terminate the MySQL Server? Typing the following in Command prompt will shut down the server completely as root user % mysqladmin -u root -p shutdown

Section A:  Use the following tables to create a database called College.  Use SQL commands. Student stuid(primary) lastName firstName

what is the need of a log in dbms