Multivalued attributes, Database Management System

Assignment Help:

For every multivalued attribute 'A', we make a new relation R that contains an attribute corresponding to plus the primary key attribute k of the relation that shows the entity type or relationship type that has as an attribute. The primary key of R is then mixture of A and k.

For instance, if a STUDENT entity has RollNo, Name and PhoneNumber where phone number is a multi-valued attribute then we will make a table PHONE (RollNo, Phone-No) where primary key is the combination. Please also reminder that then in the STUDENT table we need not have phoneNumber, instead it can be easily (Roll No, Name) only.


Related Discussions:- Multivalued attributes

Load - unload utilities, These permit the user to unload a database or part...

These permit the user to unload a database or parts of a database and reload the data on the similar machine, or on another machine in a dissimilar location. This can be useful in

What are the several kinds of the update operations relation, What are the ...

What are the several kinds of the update operations on relations? Also explain the constraints on these update operation. Give instance in support of your answer. There are th

Explain the outer join, Define Outer join Outer join - If there are any...

Define Outer join Outer join - If there are any type of values in the one table that do not have corresponding value(s) in the other, in an equi-join which will not be selected

Mixed fragmentation, Mixed fragmentation: Sometimes, horizontal fragmentati...

Mixed fragmentation: Sometimes, horizontal fragmentation or vertical fragmentation of a database schema by itself is insufficient to sufficiently distribute the data for some appli

Student, explain exhausitively the problems associated with er diagrams wit...

explain exhausitively the problems associated with er diagrams with ellustrations

What are the benefits of document scanning, What are the benefits of docume...

What are the benefits of document scanning? Document scanning, in addition to being cost-efficient, also enhances productivity. This service enhances security as you set the pa

Explain relational model and their use in dbms, Explain Relational model an...

Explain Relational model and their use in DBMS? Relational Model - The relational model was first introduced through E.F. Codd of the IBM Research in the year of 1970. The mode

Describe object relational model, Describe Object Relational model ? O...

Describe Object Relational model ? Object Relational Model - This model combines the characteristics of both relational model and object oriented model. It extends the tradit

Distributed query and transaction processing, a.  Construct a query around ...

a.  Construct a query around any one of the functional divisions you made in 4a such that if executed in the distributed design of 4 would require reconstruction of at least two ho

Define data model, Define data model? A data model is a collection of c...

Define data model? A data model is a collection of conceptual tools for explaining data, data relationships, data semantics and consistency constraints.

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