Join operation, Database Management System

Assignment Help:

The JOIN operation is applied on two relations. When we want to choose related tuples from two given relation join is used. The join operation need that both the joined relations must have at least single domain compatible attributes.

Syntax:

R1 R2 is used to join related tuples from two relations R1 and R2 into a single tuple.

is of the form:

ANDAND..............AND.

  • Degree of Relation:

Degree (R1   R2) <= Degree (R1) + Degree (R2).

  • There are three types of joins:

a)   Theta join

When every condition is of the form A θ B, A is an attribute of R1 and B is an attribute of R2 and have the similar domain, and θ is one of the comparison operators { ≤, ≥, ≠, =, <, <}.


Related Discussions:- Join operation

Which language has recently become the defacto standard, Which language has...

Which language has presently become the defacto standard for interfacing application programs along with relational database system? The language which has recently become the

What is indexed sequential file organization, What is indexed sequential fi...

What is indexed sequential file organization? What are the applications of this organization?  Ans: An index file can be employed to effectively overcome the problem of storing

Why object-oriented system use the relational dbms, Why, generally does an ...

Why, generally does an object-oriented system use the relational DBMS? The reasons for using relational DBMS for OO systems could be any combination of following: a. Many or

What is recovery?, What Is Recovery?  During the life of a transaction, ...

What Is Recovery?  During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state

What is recursive closure and operation relational algebra, What is recursi...

What is recursive closure? Why is it not possible to describe this operation in relational algebra? Recursive closure is applied to recursive relationship. An instance of rec

ERD DIAGRAM, Law Associates is a large legal practice based in Sydney. You...

Law Associates is a large legal practice based in Sydney. You have been asked to design a data model for the practice based upon the following specification: The practice employs

Explain the management of data store, Explain the Management of Data Store ...

Explain the Management of Data Store Every system irrespective of its nature of application requires storing permanent data for consequent use in problem solving. Some objects

Fundamental operations that are regular to mysql programs, What are the thr...

What are the three fundamental operations that are regular to MySQL Programs? a) Establishing a connection to the MySQL server b) Choosing a database. c) Disconnecting fr

Need point of sale software for pizza restaurant, Project Description: N...

Project Description: Need Point of Sale software for pizza restaurant. Delivery and take out service, client's database, inventory control, order history, last order, order from

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