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

Determine the advanced modeling concepts, Determine the Advanced modeling c...

Determine the Advanced modeling concepts You have to follow some steps for object-oriented design. These steps for OO Design methodology are as follow:  1)  Produce objec

Define identify relationship, Define identify relationship? Identifyin...

Define identify relationship? Identifying relationship: An identifying relationship means in which the child table cannot be uniquely recognize without the parent. For exampl

What is hierarchical dbms, What is Hierarchical DBMS In HDBMS, data is ...

What is Hierarchical DBMS In HDBMS, data is structured in a tree like manner. There is a parent-child relationship between data items and the data model is very suitable for re

Hashed file organisation, Hashed File Organisation Hashing is the most ...

Hashed File Organisation Hashing is the most common form of purely random access to a database or file. It is also used to access columns that do not have an index as an optimi

Which data type can store unstructured data, Which data type can store unst...

Which data type can store unstructured data? Raw data type can store unstructured data.

What are referential integrity constraints, What are referential integrity ...

What are referential integrity constraints? A value that appears in single relation for a given set of attributes also appears for a particular set of attributes in another rel

Anomalies, define anomalies and different types of anomalies with example

define anomalies and different types of anomalies with example

System error-database errors, System error :These contain errors in databas...

System error :These contain errors in database system or the OS, example, deadlocks.Such errors are fairly hard to detect and need reprogramming the erroneous components of the sys

What is multiplicity in the associations, What is multiplicity in the assoc...

What is multiplicity in the associations? Give an example to explain multiplicity? Multiplicity in association indicate number of objects participate in any relationship. For

Define the categories of sql statements, Define the categories of SQL State...

Define the categories of SQL Statements? 1) Statements that don't return a result set. This statement class includes INSERT, DELETE, and UPDATE. 2)Statements that return

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