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

Database system design and Implementation, Consider a typical sales invoice...

Consider a typical sales invoice that would include the following information. Design a single table to hold all of the information required to store an invoice including this info

The users who use easy-to-use menu are called, The users who use easy-to-us...

The users who use easy-to-use menu are called ? The users who use easy to use menu are called as Naïve users.

Define instance and schema, Define instance and schema?  Instance:  C...

Define instance and schema?  Instance:  Collection of  data  kept in the  data  base  at  a  particular  moment  is  known as an Instance of the database.  Schema: The o

Explain about foreign key, What is Foreign Key Foreign Key: Sometimes...

What is Foreign Key Foreign Key: Sometimes we may have to work with an attribute that does not have a primary key of its own. To recognize its rows, we have to use the primar

What are segments in oracle, What are segments in oracle? Segments - Ea...

What are segments in oracle? Segments - Each table has single field of disk space, known as segment, set aside for it in the tablespace. Segments consist of contiguous sections

List two restrictions that are applied on the modification, List two restri...

List two restrictions that are applied on the modification (updation, insertion or deletion) of base tables through view.  Ans: The two restrictions are: 1. If a view

Using relational algebra which query finds customers, Using Relational Alge...

Using Relational Algebra which query finds customers, who have a balance of over 1000 ? Using Relational Algebra Π Customer_name( σ balance >1000(Deposit)) is query to find cu

Explain about data independence, Data Independence This brings us to ou...

Data Independence This brings us to our next topic: data independence. It is the property of the database which tries to make sure that if we make any change in any level of sc

Insert into command, INSERT INTO command : Values can be inserted fo...

INSERT INTO command : Values can be inserted for all columns or for the selected columns Values can be given by sub query. In place of values parameter substitution

Define dba database administrator, Define DBA database administrator? ...

Define DBA database administrator? DBA : A database administrator (DBA) is a person who is responsible for the environmental aspects of a database. In common, these involves:

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