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
Question: (a) What do you meant by content management and briefly describe four major components of a Content Management System? (b) Explain key benefits of a Content Manage

Greater potential for bugs: Since the sites of a distributed system operate simultaneously, it is more complex to ensure the correctness of algorithms. The art of constructing dis

Do NOT use the timestamp type.  Use separate date and time data types only.  Figure out how to define an SQL insert statement that uses built-in SQL (or MySQL) functions to define

Explain the Cascadeless Schedule A cascadeless schedule is one in which for every pair of transactions Ti and Tj like that Tj reads a data item before written by Ti, the commit

Data Base Management System 1. Draw the Architecture of MySQL and explain about its subsystems briefly. 2. Elaborate with the help of an example the concept of Primary key a

Candidate Key:  In a relation R, a candidate key for R is a subset of the set of attributes of R, which have the differnt two properties: (1)        Uniqueness:                N

Add generation capabilities and/or tailor the built-in functionality of generator. This enables you to produce "all" the test data for the MySQL tables you produced in the previous

Attributes that are directly kept in the data base. For example, 'Birth date' attribute of a person.   Derived  Attributes that are not stored directly but can be derived

Self-Join:   In a self join a table is joined with itself.  Let consider the following sample partial data of EMP table EMPNO ENAME MGRID

how to construct labelled precedence graph for view serialiability.please explain insteps with one solved examples