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

Consistency error-database errors, Consistency error : These errors happen ...

Consistency error : These errors happen due to the inconsistent state of database caused may be due to wrong implementation of commands or in case of a transaction abort.  To overc

Design and build a data mart, You are required to design and build a data m...

You are required to design and build a data mart/data warehouse using Oracle. A national bank allocates funding every year for its local branches to provide temporary staff cove

Objectives of data management, The traffic data mgmt. systems infrastructur...

The traffic data mgmt. systems infrastructure plan describes the software, hardware, data network, and other elements that will support the TDMS. The infrastructure plan is based o

Two types of blocks in the fixed -length representation, What are the two t...

What are the two types of blocks in the fixed -length representation? Define them. Anchor block: Have the first record of a chain. Overflow block: Have the records other tha

Construct substantial data model, PART MARKING:  We will only mark TWO of t...

PART MARKING:  We will only mark TWO of the four questions below but you must submit answers to all four. We will choose the questions we mark randomly and we will supply you with

Access data using logical database, If one requires to access data using...

If one requires to access data using Logical Database , the use of events is unavoidable. Yes, if someone wants to access data using Logical database then the use of events

What is stored procedure, What is Stored Procedure? A stored procedure ...

What is Stored Procedure? A stored procedure is a named group of SQL statements that have been previously formed and kept in the server database. Stored procedures accept input

What is a query tree, What is a query tree?     Ans:  A query tree, as ...

What is a query tree?     Ans:  A query tree, as well known as operator graph, is a tree data structure that corresponds to a relational algebra expression. It denotes the inpu

What is null, What is NULL? Simply NULL means not in value.

What is NULL? Simply NULL means not in value.

View of data, how to submit answers softcopy

how to submit answers softcopy

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