Define views in relational algebra, Database Management System

Assignment Help:

Views in relational algebra: 

 1. Basic expression contains either 

a) A relation in the database.

b) A constant relation.

2.  General expressions are madde out of smaller sub expressions using 

a) σp(E1) select (p a predicate) 

b) ∏s(E1) project (s a list of attributes) 

c) Px(E1)rename (x a relation name) 

d) E1∪E2 union

e) E1- E2 set difference 

f) E1x x E2 cartesian product


Related Discussions:- Define views in relational algebra

Creating views with replace option, Creating views with Replace option : Th...

Creating views with Replace option : This option is used to alter the definition of the view without recreating and dropping it or regranting object privileges previously granted o

What is a database graph, What is a database graph? The partial orderin...

What is a database graph? The partial ordering implies that the set D may now be viewed as a directed acyclic graph, known as a database graph.

Large Project, Can you help me with the following: Drop statements for all...

Can you help me with the following: Drop statements for all objects in the lab project. Create statements for all objects of the lab project Create indexes for foreign keys Cre

Php optimization on iis 8, Project Description: We have purchased facebo...

Project Description: We have purchased facebook style chat software which we are using with our site. It is prepared in PHP but the rest of the site is developed asp.net. Iss

Maping constraits, #question.what is mapping constraints and types?.

#question.what is mapping constraints and types?.

Difference between operating system and database security, Difference betwe...

Difference between Operating System and Database Security Security within the operating system can be executed at various levels ranging from passwords for access to system, t

State about the use case diagram, State about the Use Case Diagram A u...

State about the Use Case Diagram A use case diagram represents a set of use cases, actors and their relationships. These diagrams shall be used to model context or requirement

What is data block, What is data block? Data Block - In oracle the data...

What is data block? Data Block - In oracle the data blocks are referred to as tablespaces. A tablespace is an fields of disk consisting of one or more disk files. A tablespace

Availability-data replication, Availability: A site having the copy of a r...

Availability: A site having the copy of a replicated relation fails, even then the relation may be found in another site. Therefore, the system may carry on to process at least th

What is cardinality ratio, What is Cardinality Ratio? Cardinality Rati...

What is Cardinality Ratio? Cardinality Ratios - The cardinality ratios for relationship kinds specifies the maximum number of relationship instances in which an entity can pa

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