What is theta join explain, Database Management System

Assignment Help:

What is theta join explain?

Theta  Join  - The  theta  join  operation  is  an  extension  to  the  natural-join operation which permits us to merge selection and a Cartesian product within a single operation. Consider relations r(R) and s(S), and let θ be a predicate on attributes in the schema R ∪ S. The theta join operation r θ s is described as follows:

r θ s = σθ (r x s)

 


Related Discussions:- What is theta join explain

What are called multilevel indices, What are called multilevel indices? ...

What are called multilevel indices? Indices with two or more levels are known as multilevel indices.

Explain the lock based protocol, Lock Based Protocol A lock is nothing ...

Lock Based Protocol A lock is nothing but a mechanism that tells the DBMS whether a particular data item is being used by any transaction for read/write purpose. As there are t

I need label printing program, Project Description: Hi I'm seeking someo...

Project Description: Hi I'm seeking someone to make my dBase application work. I know it's not a 'modern' language but it's what I know. I have written an order program and I ne

Design a gennalization and specialization hierarchy for an a, Design a genn...

Design a gennalization and specialization hierarchy for an automobile sales company

Define deadlock detection, Define Deadlock detection If a system does ...

Define Deadlock detection If a system does not employ a few protocols that make sure deadlock freedom, after that a detection and recovery scheme should be used. An algorithm

Explain how you can define an object model of a system, Explain how you can...

Explain how you can define an object model of a system. A list of terms that shall be used by end users to describe state and behaviour of objects in system.   Different use

Describe the composite key, Describe the Composite Key Composite Key: ...

Describe the Composite Key Composite Key: Sometimes one key is not enough to uniquely recognize a row. E.g. in a single class Roll is enough to search a student, but in the w

Alter table command, ALTER TABLE Command : This command is used for variati...

ALTER TABLE Command : This command is used for variation of existing structure of the table in the given situation: When a new column is to be added to the table structure.

Determine Which is not a consequence of concurrent operation, Determine Whi...

Determine Which is not a consequence of concurrent operations? Ans: Update anomaly.

Which product produces the relation that has attributes, Which product prod...

Which product produces the relation that has attributes of R1 and R2 ? Cartesian product produce the relation which has attributes of R1 and R2

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