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

Define atom of domain relational calculus, Define Atom of domain relational...

Define Atom of domain relational calculus An atom has the outline 1 , x 2 , ... , x n > -> r , in which r stands for a relation on n attributes and x 1 , x 2 , ... , x n ar

Create a database model, Submit the table creation statements (including co...

Submit the table creation statements (including constraints) for the Database Model. Submit them all in a single script file. Also submit a document explaining what test data yo

What is called bit-level striping, Normal 0 false false fal...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is difference between truncate and delete, What is difference between ...

What is difference between TRUNCATE and DELETE? - Truncate can't be rolled back whereas Delete can be. - Truncate keeps the lock on table whereas Delete keeps the lock on ea

What are the states of transaction, What are the states of transaction? ...

What are the states of transaction? The states of transaction are:- a) Active b) Partially committed c) Failed d) Aborted e )Committed   f) Terminated

Design and building a distributed information system, prototype of a distri...

prototype of a distributed information system for a national car part retail outlet chain.

Describe the host language, Describe the host language? Host Language:...

Describe the host language? Host Language: You could write applications along with SQL statements embedded inside a host language. The SQL statements give the database inter

What is meant by object-oriented data model, What is meant by object-orient...

What is meant by object-oriented data model? The object-oriented paradigm is based on encapsulation of data and code related to an object in to a one unit, whose contents are n

Describe the definition of a transaction in sql, Describe the definition of...

Describe the definition of a transaction in SQL  Ans: The SQL transaction starts implicitly. Transactions are finished by either Commit work that commits the transaction and st

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