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

Example of equijoin, Example: Consider the following relations: ...

Example: Consider the following relations: ROLLNO NAME ADDRESS COURSE_ID 100 Ka

Answer, what is database management system? & why it is required?

what is database management system? & why it is required?

Built online transaction processing, Question: A DBMS built for Online ...

Question: A DBMS built for Online Transaction Processing (OLTP) is generally regarded as unsuitable for data warehousing. Each system is designed with a different set of requir

Databases and data warehouses , Databases and data warehouses both are data...

Databases and data warehouses both are databases and both contains number of rows and columns of tables containing data. Data warehouse is really different from databases because d

What are uncommitted modifications, What are uncommitted modifications? ...

What are uncommitted modifications? The immediate-modification technique permits database modifications to be output to the database whereas the transaction is still in the act

Write short notes on transaction state, Write short notes on transaction st...

Write short notes on transaction state? A transaction may not always complete its implementation successfully such a transaction is termed aborted A transaction must be in o

Discuss the term- design optimization, Discuss the term- Design Optimizatio...

Discuss the term- Design Optimization  We have seen various ways of representing the objects.The fundamental design model uses analysis model as the framework for implementati

Implement a cache simulator, You are required to program (in a high level l...

You are required to program (in a high level language such as C, C++, Java) and implement a cache simulator which will have the following inputs and outputs:- INPUTS

Describe log based recovery, Describe log based recovery The most usabl...

Describe log based recovery The most usably structure for recording data base modification is the LOG the log is a sequence of log records recording all the update activities i

Example-revoke all on emp from mca12, Example:  //REVOKE ALL ON EMP FROM MC...

Example:  //REVOKE ALL ON EMP FROM MCA12;                              (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-

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