Design a query plan for distributed query, Database Management System

Assignment Help:

(a) Design a query plan for the following distributed query: An application at site B wants to compute a join of STUDENT ?Id=StudId TRANSCRIPT where STUDENT (Id,Major) is at site B and TRANSCRIPT (StudId, CrsCode) is at site C. The result should be returned to B. Assume that semijoin is not used. Also assume that

  • Value lengths are:
  1. Id and StudId are 8 bytes long;
  2. Major is 3 bytes long;
  3. CrsCode is 6 bytes long.
  • STUDENT has 15,000 tuples.
  • 6,000 students are registered for at least one course. On the average, each student is registered for 5 courses.

(b)   Estimate the cost of computing σMajor='CS' (STUDENT) ?Id = StudId TRANSCRIPT using the semijoin strategy. Use the sizes of the STUDENT and TRANSCRIPT relations and of their attributes from the part (a) above. In addition, assume that 10% of the students major in CS. Compare this with the solutions in part (a) above that do not use the semijoin.

 


Related Discussions:- Design a query plan for distributed query

Describe the algorithm for updating indices, Describe the algorithm for upd...

Describe the algorithm for updating indices for a single level index when a record is    (i) Inserted  (ii)  deleted What will be the modification if there are multilevel in

Describe the association - design, Describe the Association: Design  ...

Describe the Association: Design  Before we describe association design let us define association "Association is set of links between two objects in the object model". It is

What is data integrity, What is data integrity? Ans: It is the data con...

What is data integrity? Ans: It is the data consisted of in database that is accurate and consistent.  (Data integrity means that the data should be valid as per to the give

Designing the database schema , The domain that you will model in this assi...

The domain that you will model in this assignment is that of courses and students at a university. So as not to make the task too large and unspecified, you will here get a descrip

Define network dbms, Define Network DBMS The NDBMS is built primarily o...

Define Network DBMS The NDBMS is built primarily on a one-to-many relationship, but where a parent-child representation between the data items cannot be ensured. This may occur

Define assertions in sql, Define Assertions in SQL a. An assertion is a...

Define Assertions in SQL a. An assertion is a predicate that is expressing a condition we wish the database to always satisfy.  b. Domain constraints, functional dependency

Pl/SQL, I need solution of the question posted at http://www.expertsmind.c...

I need solution of the question posted at http://www.expertsmind.com/questions/sql-query-for-testing-triggers-and-stored-procedures-30140149.aspx

Describe the menu based interfaces for web clients browsing, Describe the M...

Describe the Menu based interfaces for web clients or browsing? Menu-Based Interfaces for Web Clients or Browsing - These interfaces present the user along with lists of option

Design an algorithm to implement operations, Design an algorithm to impleme...

Design an algorithm to implement operations  Each and every operation specified in the functional model could be formulated as an algorithm. The algorithm indicates how operat

Explain two phase locking protocol, Explain Two phase locking protocol ...

Explain Two phase locking protocol A transaction is consider as to follow the two-phase locking protocol if all locking operations precede the first unlock operation in the tra

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