Describe the nested-loop join and block-nested loop join, Database Management System

Assignment Help:

Describe the nested-loop join and block-nested loop join. 

 Ans:   The block nested- loop join algorithm is as described below:   

 for every block Br of relation R do begin       

   for every block Bs of  relation S do begin    

    for every tuple tr in Br do begin    

     for every tuple ts in Bs do begin   

      test pair (tr,ts) to see if they satisfy the join  

     condition                                      

        if they do, add tr.ts to the result  

     end

    end

   end

 end          

  The nested-loop from algorithm is like this: 

  for every tuple tr in relation R do begin

                for every tuple ts in relation S do begin

   test pair (tr,ts) to see if they satisfy the join condition   

    if they do, add tr.ts to the result

                     end

      end


Related Discussions:- Describe the nested-loop join and block-nested loop join

Non-query optimisations, Part: Recommended (Non-query) Optimisations Thi...

Part: Recommended (Non-query) Optimisations This section entitled "Recommended (non-query) optimisations" should be a brief report containing recommended optimisations you would

Illustrate the cardinality of relationship, Cardinality of Relationship ...

Cardinality of Relationship One-to-One Only one entity of the first set is linked to only one entity of the second set. E.g. A teacher teaches a student. Only one teacher

Create a er diagram to show customer accounts, Information about a bank is ...

Information about a bank is about customers and their account. Customer has a name, address that consists of house number, area and city, and one or more phone numbers. Account ha

Explain object oriented model, Explain Object oriented Model ? Object ...

Explain Object oriented Model ? Object Oriented Model - This model is based on the object-oriented programming language paradigm. It involves the features of OOP such as inhe

List any two disadvantages of a database system, List any two disadvantages...

List any two disadvantages of a database system ? The disadvantages of database system are: • Database systems are difficult, complex, and time-consuming to design. • Substanti

Benefits of views-data control, Benefits: It limits data access. ...

Benefits: It limits data access. It makes difficult queries look easy. It permits data independence. It presents dissimilar views of the similar data.

Transactions and concurrency management, Transactions And Concurrency Manag...

Transactions And Concurrency Management  Introduction One of the main benefits of storing data in an integrated repository or a database is to permit sharing of it betwee

What is meant by functional dependencies, What is meant by functional depen...

What is meant by functional dependencies? Consider a relation schema R and α C R and β C R. The functional dependency α ->β  holds on relational schema R if in any legal relati

Define lock, Define lock? Lock is the most common used to execute the r...

Define lock? Lock is the most common used to execute the requirement is to permit a transaction to access a data item only if it is currently holding a lock on that item.

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