Relational DB, Database Management System

Assignment Help:
Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if:
1.1 The only key is A1.
1.2 The only key is A1 and A2.
1.3 The only key is {A1 A2} and {A3 , A4}.
1.4 The only key is {A1 A2} and {A1 , A3}.

Related Discussions:- Relational DB

Weak entity, Entity types that do not have any key attribute, and therefore...

Entity types that do not have any key attribute, and therefore cannot be identified independently, are known as weak entity types. A weak entity can be recognized uniquely only by

Case snerio, each publisher has uniqe name a mial addrs are also kept on ea...

each publisher has uniqe name a mial addrs are also kept on each pubisher.a publisher publish one book.a book publish y one publisher.book identified by isbn.each book writn by one

What are the ways in which signal can be generated, What are the ways in wh...

What are the ways in which signal can be generated A signal might be generated in many ways such as a Signal is result of particular physical condition. Whenever a process writ

Fire dementpart, The State of NewYork certifies firefighters throughout sta...

The State of NewYork certifies firefighters throughout state and keep track all of them, as well as of the state’s fire departments. Each fire department has unique department numb

Insert into command, INSERT INTO command : Values can be inserted fo...

INSERT INTO command : Values can be inserted for all columns or for the selected columns Values can be given by sub query. In place of values parameter substitution

Describe deductive databases and relational databases, Problem : (b) A ...

Problem : (b) A deductive database system is essentially the outcome of applying mathematics logic to database management, where logic is used for both data representation and

What is transaction, What is transaction? Transaction is a unit of prog...

What is transaction? Transaction is a unit of program implementation that accesses and possibly updated several data items.

Explain trivial dependency, Explain trivial dependency? Functional depe...

Explain trivial dependency? Functional dependency of the form α ->β. is trivial if α C β. Trivial functional dependencies are satisfied by all the relations.

Define union compatibility, Define union compatibility? Explain why INTERSE...

Define union compatibility? Explain why INTERSECTION of two relations cannot be performed if they are not union compatible? Two relations R(A1, A2,-------, An) and S(B1, B2,--

Briefly describe concurrency execution, Briefly describe concurrency execut...

Briefly describe concurrency execution? Lock - based protocols Locks There are several modes in which a data item may be locked in this section we restrict our attention

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