Define functional and multivalued dependencies, Database Management System

Assignment Help:

Define functional and multivalued dependencies.      

Ans:  A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how attributes relate to one another, and identify the functional dependencies between attributes. While a functional dependency is available, the dependency is fixed as a constraint among the attributes. Refer a relation with attributes A and B, in which attribute B is functionally dependent on attribute A. If we know the value of A and we inspect the relation that holds this dependency, we will find out just only one value of B in all of the tuples which have a given value of A, at any moment in time. Note though, that for a given value of B there may be various different values of A. 

Multivalued Dependencies:  A multivalued dependency is an outcome of two independent 1: N relationships A: B and A: C being mixed in similar relation R(A,B,C)


Related Discussions:- Define functional and multivalued dependencies

Create a entity-relationship diagrams, This project requires you to create ...

This project requires you to create a database design.  Your design will be documented in a set of Entity-Relationship diagrams.  Draw a set of Entity-Relationship diagrams to mode

Define the terms- ddl and dml, Define the terms   i) DDL   ...

Define the terms   i) DDL   ii) DML   DDL: Data base schema is specified by a set of definitions expressed by a special   language known as a data def

What is boyce-code normal form, Boyce-Code Normal Form (BCNF) A relatio...

Boyce-Code Normal Form (BCNF) A relationship is said to be in BCNF if it is already in 3NF and the left hand side of each dependency is a candidate key. A relation who is in 3N

What are the problems in database normalization, What are the problems if o...

What are the problems if one were not to normalize?  When do these problems surface?           Ans:  Database normalization, sometimes considered to as  canonical synthesis, is

Aims of the design project, The aims of the project are: 1. To enable th...

The aims of the project are: 1. To enable the students to undertake the detailed design of a specific plant or process 2. The design projects includes: process selection; und

What is meant by mean time to failure, What is meant by mean time to failur...

What is meant by mean time to failure? The mean time to failure is the amount of time that the system could run continuously without failure.

Define signal, Define Signal. It allows methods to respond to events tr...

Define Signal. It allows methods to respond to events triggered by themselves or by other processes. Each signal corresponds to an exacting event. A signal is represented in Sy

Improved performance, Improved performance: As the data is located near the...

Improved performance: As the data is located near the site of its demand, and given the inherent parallelism because of multiple copies, speed of database access may be good for di

What is oracle process explain for processes of oracle, What is Oracle Proc...

What is Oracle Process? Explain any four processes started by Oracle. Oracle Process is as follows: SMON: The System Monitor carries out a crash recovery while a crashed in

What is called as an n-way merge, What is called as an N-way merge? The...

What is called as an N-way merge? The merge operation is a generalization of the two-way merge used by the standard in-memory sort-merge algorithm. It merges N runs, so it is k

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd