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

How to apply the bcnf decomposition , Consider the following relational sch...

Consider the following relational scheme: R (a,b,c,d,e,f) and its corresponding set of FDs {d→ a, be → c, ac → e, b → f, f → d, a → c}. a. Is the following decomposition i) non

Atomicity-transaction , Atomicity: It describes a transaction to be a one ...

Atomicity: It describes a transaction to be a one unit of processing. We can also say either a transaction will be finished completely or not at all. In the transaction example 1

Query by example, Illustrate how you can use QBE to perform logical AND and...

Illustrate how you can use QBE to perform logical AND and OR operation

Explain the structured decomposition, Differentiate between the object orie...

Differentiate between the object oriented decomposition and the structured decomposition? Process-oriented (structural) decomposition divides a complex process, function or tas

What is conceptual schema, What is conceptual schema? The schemas at th...

What is conceptual schema? The schemas at the view level are known as subschema that describe dissimilar views of the database.

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

Access, I have to solve a problem using access

I have to solve a problem using access

Define query optimization, Define query optimization. Query optimizatio...

Define query optimization. Query optimization refers to the process of search the lowest -cost method of evaluating a given query.

E-r model uses this symbol to represent weak entity set, E-R model uses thi...

E-R model uses this symbol to represent weak entity set ? A Doubly outlined rectangle symbol is used to represent weak entity set.

Normalization assigment, what would go in order patient#, patient name, pat...

what would go in order patient#, patient name, patien address, surgeon#, surgeon name, surgery date, surgery type, drug admin

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