What are partial and natural key, Database Management System

Assignment Help:

What are partial, alternate,, artificial, compound and natural key?

Partial Key: It is a set of attributes that can uniquely recognize weak entities and that are related to same owner entity. It is sometime known as Discriminator.

Alternate Key: All Candidate Keys excluding the Primary Key are called as Alternate Keys.

Artificial Key: If no obvious key either stands alone or compound is available, then the last resort is to simply make a key, by assigning a unique number to every record or occurrence. Then this is known as developing an artificial key.

Compound Key: If no single data element uniquely identifies occurrences within a construct, then combining multiple elements to make a unique identifier for the construct is known as creating a compound key.

Natural Key: When one of the data elements stored within a construct is utilized as the primary key, then it is known as the natural key.

 


Related Discussions:- What are partial and natural key

What is the need of a log in a dbms, What is the need of a log in a DBMS? B...

What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log.            Ans:  The system log, which is generally writt

Natural join-table handling, Natural Join : It is the similar like Equi joi...

Natural Join : It is the similar like Equi join except one of the duplicate columns is removed in the result table. The natural join is the most usually used form of join operation

What is relational calculus, What is Relational calculus? Relational c...

What is Relational calculus? Relational calculus is a Non- Procedural language.

Employee elation with information, Consider a database application that dea...

Consider a database application that deals with an Employee relation with information such as SIN, name, data of birth (DOB), and DID (the ID of the department at which the employe

What is known as a search key, What is known as a search key? An attrib...

What is known as a search key? An attribute or set of attributes used to look up records in a file is known as a search key.

Cataloguing, differences between a classified catalog and a dictionary cata...

differences between a classified catalog and a dictionary catalog

Explain discretionary access control, Problem: (a) Given the following ...

Problem: (a) Given the following relation: Stats(Name,Sex,Children, Occupation, Salary, Tax, Audits) Write SQL code to define the following security constraints: (i) User

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

Explain the terms data warehousing and data mining, Question: i) Explai...

Question: i) Explain the terms data warehousing and data mining. ii) Discuss the importance of the following security principles that a digital firm should amongst others, n

What is a recursive relationship, What is a recursive relationship? Give an...

What is a recursive relationship? Give an example not used in the text. A recursive relationship is a relationship among an entity and itself. For example, given the entity PER

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