Explain projection operation distribute over union operation, Database Management System

Assignment Help:

Illustrate the statement 'Projection operation distributes over the union operation'. Give an example.   

Ans: ΠL(E1 ∪ E2) = (ΠL(E1)) ∪ (ΠL(E2))  

This says that result acquired by projecting on an attribute set A, after taking union of two relations is similar as union of two relations each of which is a projection of original relations on A.


Related Discussions:- Explain projection operation distribute over union operation

What are the time stamps associated with each data item, What are the time ...

What are the time stamps associated with each data item? W-timestamp (Q) denotes the largest time stamp if any transaction that implemented WRITE (Q) successfully. R-timesta

Explain the timestamp ordering protocol, Timestamp Ordering Protocol A ...

Timestamp Ordering Protocol A timestamp is a tag that can be attached to any transaction or any data item, which indicates a specific time on which the transaction or data item

Please answer me., gyan gurukul is a software company that provides softwar...

gyan gurukul is a software company that provides software related solution.

What is the archtetype pattern, What is the archtetype/instance pattern? ...

What is the archtetype/instance pattern? The archetype/instance pattern happens when one entity tracks occurrences of another entity. A common example is the relationship among

Describe the ways for selecting data structure, Ways for Selecting Data Str...

Ways for Selecting Data Structure Algorithms operate on data structure. Therefore, selection of the best algorithm means selecting the best data structure from whole bunch. Th

Prepare a site map and submit it in bing and google, Project Description: ...

Project Description: I am updating my Javascript + HTML website with five domains for the same website I would like to know if I want to create site map and submit it in all the

Authorisation, Authorisation Authorisation is the culmination of the ad...

Authorisation Authorisation is the culmination of the administrative policies of the organisation.  As the name shows, authorisation is a set of rules that can be used to verif

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