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

What are the causes of bucket overflow in a hash file, What are the causes ...

What are the causes of bucket overflow in a hash file organization? What can be done to reduce the occurrence of bucket overflow? When a record is inserted, the bucket to that

Student, explain exhausitively the problems associated with er diagrams wit...

explain exhausitively the problems associated with er diagrams with ellustrations

What is the need for triggers, What is the need for triggers? Triggers ...

What is the need for triggers? Triggers are useful mechanisms for alerting humans or for starting particular tasks automatically when particular conditions are met.

Differentiate sub-class and super-class, Differentiate sub-class and super-...

Differentiate sub-class and super-class? The specialization of a class is known as subclasses.eg: employee is a subclass of person and teller is a subclass of employee. Convers

What is gathering information and producing erd, What is Gathering informat...

What is Gathering information and Producing ERD Gathering information: This could be a written document that explains the system in question with reasonable quantity of detai

Describe difference between a one-to-many and a many-to-many, Describe the ...

Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?

What way a particular application views data from database, What is the way...

What is the way a particular application views the data from the database that the application uses? Sub schema is the way a particular application views the data from the data

DW, #ques Define a job scheduling strategy that will meet business requirem...

#ques Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a p

Define assertions in sql, Define Assertions in SQL a. An assertion is a...

Define Assertions in SQL a. An assertion is a predicate that is expressing a condition we wish the database to always satisfy.  b. Domain constraints, functional dependency

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