What is the difference between a key and a superkey, Database Management System

Assignment Help:

What is the difference between a key and a superkey?

Key - A key a single attribute or a combination of two or more attributes of an entity set which is used to identify one or more examples (rows) of the set (table). It is a minimal combination of attributes.

Super Key - A super key is a set of one or more attributes in which, taken collectively, permits us to identify uniquely a tuple within the relation.


Related Discussions:- What is the difference between a key and a superkey

Explain what is relation, Explain What is Relation? A database relatio...

Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.

What is first normal form, What is first normal form? The domain of att...

What is first normal form? The domain of attribute must contain only atomic (simple, indivisible) values.

Define the concept of design documentation, Design Documentation  The ...

Design Documentation  The Design Document shall be an extension of Requirements Analysis Design. "The Design Document will comprise a revised and much more detailed descrip

Database models, why are older data models are being replaced by new data m...

why are older data models are being replaced by new data models

In an e-r diagram how attributes are represented, In an E-R diagram how att...

In an E-R diagram how attributes are represented ? In an E-R diagram attributes are represented in a ellipse.

Using column aliases-data manipulation language, Using Column aliases E...

Using Column aliases Example: To print column names as NAME and ANNUAL SALARY SELECT ENAME "NAME", SAL*12 "ANNUAL SALARY" FROM EMP;

Define physical and logical data independence, Define physical and logical ...

Define physical and logical data independence. How does this architecture help in achieving these? Data independence entails that change in one view must not need a change in t

Define catalog and meta data, Define Catalog and meta data ? A catalog ...

Define Catalog and meta data ? A catalog is a compilation of records elaborating the contents of a particular collection or group of collections. Metadata (Meta data, or someti

Entity set that does not have sufficient attributes known as, An entity set...

An entity set that does not have sufficient attributes to form a primary key is called? An entity set that doesn't have sufficient attribute to form a primary key is known as w

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