Prove that a relation which is 4nf must be bcnf, Database Management System

Assignment Help:

Prove that a relation which is 4NF must be BCNF.  

Ans Let R be in 4NF.  Suppose it is not in BCNF.  Hence, there exists an FD X→Y in R such that x is not a super key. Although by the rule M1 X→Y|=x→→Y. Once again x here is not a super key.  This contradicts the fact that R is in 4NF.  Hence, our assumption is false.  Each R in 4NF should be in BCNF.


Related Discussions:- Prove that a relation which is 4nf must be bcnf

Explain in detail about collaboration diagrams, Explain in detail about Col...

Explain in detail about Collaboration Diagrams Collaboration diagrams are interaction diagrams which emphasize structural organisation of an object that transmit and receive m

Candidate keys, Super keys of a relation can have extra attributes. Candida...

Super keys of a relation can have extra attributes. Candidate keys are minimal super key, i.e. such a key have no extraneous attribute. An attribute is known as extraneous if even

Abap/4 program, It is not possible to make an ABAP/4 program, which having ...

It is not possible to make an ABAP/4 program, which having only Subroutines. False. We can make ABAP/4 program, which having only Subroutines.

Determine the types of methods for retrieving rows in python, Describe the ...

Describe the two types of methods for retrieving rows in Python? Fetchone()- Returns the next row as a sequence Fetch all()- Returns the entire result set like a strin

Describe relational model, Describe relational model? Structure of rela...

Describe relational model? Structure of relational data base Basic structure Database schema Keys Schema diagram Query languages

What is meant by normalization of data, What is meant by normalization of d...

What is meant by normalization of data? It is a process of examining the given relation schemas based on their Functional Dependencies (FDs) and primary key to achieve the prop

Multiple column queries-syntax, Multiple column Queries: Syntax: ...

Multiple column Queries: Syntax: SELECT COLUMN1, COL2,...... FROM TABLE WHERE (COLUMN1, COL2, ...) IN (SELECT COLUMN1, COL2,....  FROM TABLE WHERE );

Serialisability, Serialisability: Any schedule that makes the similar resul...

Serialisability: Any schedule that makes the similar results as a serial schedule is known as a serialisable schedule. But how can a schedule are determined to be serialisable or n

Objectives-the structured query language, Objectives After reading this...

Objectives After reading this part, you should be able to: Modify, create, and delete database schema objects; Update database using SQL command; Retrieve data f

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