Example of relational operations, Database Management System

Assignment Help:

Consider the relation PERSON. If you want to display details of persons having age less than or equal to 30 than the select operation will be used as follows:

σ AGE <=30 (PERSON)

The resultant relation will be as shown:

PERSON_ID

NAME

AGE

ADDRESS

2

Sharad Gupta

30

Pocket 2, Mayur

Vihar.

 

 

 

Note:

1)   Select operation is commutative; i.e.,

σ (R)) = σ (R))

Therefore, series of select can be applied in any order

2) More than one condition can be applied using Boolean operators OR & AND etc.


Related Discussions:- Example of relational operations

Determine the Disadvantages of file based systems, Determine the Disadvanta...

Determine the Disadvantages of file based systems Some of the disadvantages of file based systems are like this: Data redundancy and inconsistency: the dissimilar applic

boyce codd normal form relations, Create centralized relational database u...

Create centralized relational database using bottom up method.   (a) Recognize a single un-normalized relation for the above scenario.          (b) Recognize the primary key for

Skills required, wrie a report on whether a BSc n information systems devel...

wrie a report on whether a BSc n information systems develops the skills required by employers in Database administration

What is ocr, What is OCR? OCR (Optical Character Recognition) is a tech...

What is OCR? OCR (Optical Character Recognition) is a technology that enables you to change different types of machine-readable documents, like scanned paper documents, PDF fil

Describe analysis of access paths, Describe analysis of access paths To...

Describe analysis of access paths To describe analysis of access paths, consider an example of the design of a company's employee skills database. A part of the object model fr

The sap profile parameter, While sorting, if the main storage available is ...

While sorting, if the main storage available is not enough, the system writes data to an external help file.  The SAP profile parameter, which determines DIR_SORTTMP

Explain the shadow paging recovery technique, Explain the shadow paging rec...

Explain the shadow paging recovery technique.  Ans: Shadow paging is a method used to acquire atomic and durable transactions, and provides the capability to manipulate pages i

Sql, sql is relationally complete-justify

sql is relationally complete-justify

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