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

Write short notes on index structure of files, WRITE SHORT NOTES ON INDEX S...

WRITE SHORT NOTES ON INDEX STRUCTURE OF FILES? There are two basic parts of indices 1.   Ordered indices 2.   Hash indices Every technique must be evaluated on the bas

Explain categories of failures that occur in oracle database, Explain diffe...

Explain different categories of failures that occur in Oracle database? Categories of Failures - In Oracle database subsequent types of failures can occurred: Statement Failu

Max. no. of structures in a table or structure, What is the max. no. Of str...

What is the max. no. Of structures that can be included in a table or structure. Nine.

B2b business uk database, We have a new website where I need someone to 1: ...

We have a new website where I need someone to 1: Inhabit the back end with all the recruitment agencies in the UK. I require someone who is not manually going to do this, but who w

Join operation, The JOIN operation is applied on two relations. When we wan...

The JOIN operation is applied on two relations. When we want to choose related tuples from two given relation join is used. The join operation need that both the joined relations m

Explain displaying an er schema as an er diagram, Explain the conventions f...

Explain the conventions for displaying an ER schema as an ER diagram? An E-R Diagram scheme might describe certain constraints to that the contents of a database must conform.

Discuss how the bi-directional implementations are made, Discuss how the bi...

Discuss how the bi-directional Implementations are made. In bi-directional implementation of the association, a pair of references must implement every link. The declarations a

Explain the term- query, Explain the term- Query. Queries are used to re...

Explain the term- Query. Queries are used to repossess and show specific records in a table. They can also be used to show specific fields of specific records, which meet the co

Define the terms - physical schema and logical schema, Define the terms  1)...

Define the terms  1) physical schema 2) logical schema.  Physical schema:  The physical schema explains the database design at the physical level, which  is  the  lowest  lev

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