Super keys, Database Management System

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.

Posted Date: 3/6/2013 5:23:51 AM | Location : United States







Related Discussions:- Super keys, Assignment Help, Ask Question on Super keys, Get Answer, Expert's Help, Super keys Discussions

Write discussion on Super keys
Your posts are moderated
Related Questions
Explain the functions of data manager? Functions of Data Manager : - Convert operations in user's queries coming directly through query processor or indirectly in an applicatio

What is the most significant feature that does not directly map into programming language structures? Why? Association, since there are complex types of association, like as qu

Example: Consider the following relations: ROLLNO NAME ADDRESS COURSE_ID 100 Ka

What are the two integrity rules?  Ans:  The two integrity rules are: Entity Integrity Rule & Referential Integrity Rule.   Entity Integrity Rule - If the attribute A of rel

Adding Redundant Associations for Efficient Access Redundant associations do not add any type of information, therefore during design we should actually examine structure of o

Primary Key The primary key is the candidate key that is selected by the database designer as the principal denotes of identifying entities within an entity set. The left candi

Explain Authorization and Integrity Manager ? Authorization and Integrity Manager: Tests for the satisfaction of integrity constraints and checks the authority of users to acce

Explain the Concept of Two-phase Locking It concerns the positions of locking and unlocking operations in each transaction.  In this protocol every transaction issue lock and u

Which operator is Cartesian product in relational algebra? Cartesian product in relational algebra is a binary operator. (It requires two operands. e.g., P X Q)

What is Identity? Identity (or AutoNumber) is a column that automatically produces numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID