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

ER DIAGRAM, NEED ER DIAGRAM WITH MINIMUM ENTITY AND RELATIONSHIP of Hospita...

NEED ER DIAGRAM WITH MINIMUM ENTITY AND RELATIONSHIP of Hospital Management System

Inconsistent analysis-problems of concurrent transactions, Inconsistent Ana...

Inconsistent Analysis : The problem as given with transactions T1 and T2 where two transactions interleave to make incorrect result during an analysis by Audit is the instance of s

What purpose of tables, What is the purpose of tables, private synonyms and...

What is the purpose of tables, private synonyms and public synonyms? If there are multiple objects of similar name on an Oracle database, that order are they accessed in? The r

Dbms, You are managing the following database system: • DBMS: Oracle 11g ...

You are managing the following database system: • DBMS: Oracle 11g • OS: Sun Solaris • System architecture: Web-based application using ASP.Net • Purpose of Server: HR managem

Concurrent transactions-backup and recovery, Representing complex relations...

Representing complex relationship among data A database may contain varieties of data interrelated to each other in numerous ways. A DBMS must have the capability to represent

Fragmentation, Differentiate between horizontal & mixed horizontal fragment...

Differentiate between horizontal & mixed horizontal fragmentation?

Describe relational model, Describe relational model? Structure of rela...

Describe relational model? Structure of relational data base Basic structure Database schema Keys Schema diagram Query languages

Digital, #floating point representation is used to store

#floating point representation is used to store

Descrine an data dictionary, Describe an data dictionary? A data dictio...

Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.

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