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

Describe physical data independence, Describe Physical Data independence ? ...

Describe Physical Data independence ? Physical Data Independence - It is capacity to modify the internal schema without having to change conceptual schema. Therefore, the exter

Managing Data in Databases, Answer SQL Queries to extract data from data ta...

Answer SQL Queries to extract data from data tables and questions on mapping conceptual data models into relational data model.

Timestamp type, Do NOT use the timestamp type.  Use separate date and time ...

Do NOT use the timestamp type.  Use separate date and time data types only.  Figure out how to define an SQL insert statement that uses built-in SQL (or MySQL) functions to define

What are the ways in which signal can be generated, What are the ways in wh...

What are the ways in which signal can be generated A signal might be generated in many ways such as a Signal is result of particular physical condition. Whenever a process writ

Explain the terms primary key, Explain the terms primary key, candidate key...

Explain the terms primary key, candidate key, alternate key and secondary key. In the given table identify every key? STUDENT(SID,Regno, Name, City) Primary Key: The prim

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