Super keys, Database Management System

Assignment Help:

A super key is an attribute or set of attributes used to recognize the records uniquely in a relation.

For instance, in the Relation PERSON defines earlier PERSON_ID is a super key since PERSON_ID is unique for every person. Likewise (PERSON_ID, AGE) and (PERSON_ID, NAME) are also super keys of the relation PERSON as their combination is also unique for each record.


Related Discussions:- Super keys

Referential integrity, It can be easily defined as: The database must no...

It can be easily defined as: The database must not have any unmatched foreign key values. The term "unmatched foreign key value" means a foreign key value for which there doe

Economics, Economics: It is now usually accepted that it costs less to make...

Economics: It is now usually accepted that it costs less to make a system of smaller computers with the equivalent power of a one large computer. It is more cost-effective to get s

Describe identifying relationship, Describe identifying relationship? ...

Describe identifying relationship? Identifying relationship: It is relationship among strong entity and a weak entity it is represented through a doubly outlined diamond in C

The transactions, The Transactions- A transaction is definite as the unit o...

The Transactions- A transaction is definite as the unit of work in a database system. Database systems that deal with a huge number of transactions are also termed as transaction p

Illustration of implementation of inheritance, Illustration of implementati...

Illustration of implementation of inheritance Let us take the illustration of implementation of inheritance. Suppose that we are about to implement the Stack class and by now w

What are the causes of bucket overflow in a hash file, What are the causes ...

What are the causes of bucket overflow in a hash file organization? What can be done to reduce the occurrence of bucket overflow? When a record is inserted, the bucket to that

A basic model of database access control, A basic model of Database Access ...

A basic model of Database Access Control Models of database access control have grown out of previous work on protection in operating systems. Let us talk about one simple mode

What is omr, What is OMR? OMR (Optical Mark Recognition) is the transla...

What is OMR? OMR (Optical Mark Recognition) is the translation of marks - or the absence of marks - but not the shape of the mark on forms that have small circles ("also called

Describe difference between a one-to-many and a many-to-many, Describe the ...

Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?

Two phase locking (2pl), Two Phase Locking (2PL) The two-phase locking ...

Two Phase Locking (2PL) The two-phase locking protocol having of two phases: Phase 1 : The lock acquisition phase : If a transaction T needs to read an object, it wants to

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