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

Gui interfaces, Draw the database using the ER approach and then make the t...

Draw the database using the ER approach and then make the tables accordingly. Populate the tables so that every table have at least 10 tuples. Then using Java and SQL, execute the

Introduction to database technology, 1. Create the tables for the play-sche...

1. Create the tables for the play-scheme database as specified in the TMA. 2. Enter the data as given in the spreadsheet. 3. Create queries to retrieve specified information

Which model is used to store data in tree structures, 1. Which model is use...

1. Which model is used to store data in tree structures Ans: Hierarchical model is used to store data in tree structures

How is concurrency identified, How is concurrency identified? Concurren...

How is concurrency identified? Concurrency in objects can be identified by the way they alter their state. Current objects can change their state independently. Aggregation imp

What is a recursive relationship, What is a recursive relationship? Give an...

What is a recursive relationship? Give an example not used in the text. A recursive relationship is a relationship among an entity and itself. For example, given the entity PER

Database administrator, Database Administrator One of the main perpos...

Database Administrator One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having li

Can you delete data element, Can we delete data element, which is being use...

Can we delete data element, which is being used by table fields. No we cant delete data element.

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

Construct an er diagram for a hospital, Construct an ER diagram for a hospi...

Construct an ER diagram for a hospital along with a set of patients and a set of medical doctors Associate with every patient a log of the several tests and examinations conducted.

ER diagrams, explain exhaustively the problems associated with ER diagrams....

explain exhaustively the problems associated with ER diagrams. include illustrations in your answer

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