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

Define the terms entity, Define the terms entity, attribute, role and relat...

Define the terms entity, attribute, role and relationship between the entities, giving examples for each of them.         Ans: Entity:   An entity is a "thing" or "object" in th

Describe the iterative and incremental life cycle, Describe the iterative a...

Describe the iterative and incremental life cycle For an iterative and incremental life cycle, two criteria are process and time. The main components of showing a project devel

How many types of data independence have, Types of data independence D...

Types of data independence Data independence can be classified into the following two types: Physical Data Independence: This means that for any change made in the physi

Describe the menu based interfaces for web clients browsing, Describe the M...

Describe the Menu based interfaces for web clients or browsing? Menu-Based Interfaces for Web Clients or Browsing - These interfaces present the user along with lists of option

Query to list the employee name have 10000 salary, Consider employee table ...

Consider employee table of (i) and list names of department(s) for which average salary for department is more than 10,000. (SELECT d_name FROM dept WHERE d_code IN (SELECT d_c

Which is another name for weak entity, Which is another name for weak entit...

Which is another name for weak entity? Child is another name of weak entity.

RDM & ER Modelling, #questiRegional Gardens has many nurseries, including W...

#questiRegional Gardens has many nurseries, including Wagga Wagga, Bathurst, Albury, Orange, and Dubbo. Each nursery is known by its campus code, eg WW, B, A, O and D respectively.

What does conceptual design work, What does conceptual design work? A c...

What does conceptual design work? A conceptual design involves modelling independent of the DBMS.

What are the basic objects of the data dictionary, What are the basic objec...

What are the basic objects of the data dictionary? Tables Domains Data elements Structures Foreign Keys

Explain data abstraction, Explain data abstraction? Data abstraction Da...

Explain data abstraction? Data abstraction Data abstraction is a methodology in which enables us to isolate how a compound data object is utilized from the details of how it is

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