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 several forms of identity, What are the several forms of ident...

What are the several forms of identity? a) Value b) Name c) Built-in

Define deadlock recovery measures, Define Deadlock recovery measures       ...

Define Deadlock recovery measures                   To recover from deadlock, the cycle in the wait-for-graph should be broken. The common technique of doing this is to rollbac

What type of view of total database content, What type of view of total dat...

What type of view of total database content? Data base content Conceptual view of total database contain.

Strict 2pl-two phase locking (2pl), Strict 2PL :Though, this basic 2PL suff...

Strict 2PL :Though, this basic 2PL suffers from the trouble that it can result into loss of isolation / atomic property of transaction as theoretically speaking once a lock is rele

Describe the development process of object oriented methods, Describe the d...

Describe the development process of Object oriented methods Object oriented methods have roots which are strongly anchored back in the 60s, functional and structured methods we

What is the difference between link and reference, What is the difference b...

What is the difference between link and reference? The fundamental difference between links and references is that links are symmetrical on the other hand references refer only

What is the used of specifying alias, What is the used of specifying alias?...

What is the used of specifying alias? Specifying alias: is used to rename column or attribute in a table.

Explain instance and schemas, Explain Instance and schemas? Instances ...

Explain Instance and schemas? Instances and schemas: Databases changes over time as the information is deleted and inserted. The collection of information stored in database

Extended star schema, Northwind Pty Ltd sells a variety of food products th...

Northwind Pty Ltd sells a variety of food products throughout the world.  They want to use the reporting features of SAP's Business Information Warehouse to better understand their

What is cross product, What is Cross Product? Simply Cross product is B...

What is Cross Product? Simply Cross product is Binary Operator

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