When are two schedules said to be view equivalent, Database Management System

Assignment Help:

When are two schedules said to be view equivalent?    

Ans: Two schedules that is denoted as S and S' are said to be view equivalent if the subsequent three conditions are met

1)  For every data item Q, if a transaction Ti reads the initial value of Q in schedule S, after that transaction Ti should in schedule S'  also read the initial value of Q.

2)  For every data item Q, if a transaction Ti executes read(Q)  in schedule S and that value was generated by Tj (if any) , then transaction Ti must in schedule S'  as well read the value of Q generated by Tj.

3)  For every data item Q, if a transaction if any that carries out the final write(Q) in schedule S should perform the final write(Q) in schedule S'.


Related Discussions:- When are two schedules said to be view equivalent

Information infrasture, what benefit can a company gain by managing its own...

what benefit can a company gain by managing its own infrasture and services

Explain how the law ensures data protection and security, Question 1: (...

Question 1: (a) Explain the legal meaning of :- (i) Computer Service Person (ii) Data holding (b) Explain how the law ensures Data protection and Security. Qu

What is the use of raid, What is the use of RAID? A variety of disk-org...

What is the use of RAID? A variety of disk-organization methods, collectively called redundant arrays of independent disks are used to better the performance and reliability.

Improve efficiency of database, Smart Alex Catering Sevice (SACS) is a comp...

Smart Alex Catering Sevice (SACS) is a company offering top class catering staff  for prestigious events.  The company employs approximately 200 hourly paid contact staff - chefs,

What is the meaning of recovery, What is the meaning of Recovery? In d...

What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO

What is functional dependency, A Functional dependency is described by ...

A Functional dependency is described by X Y between two groups of attributes Y and X that are subsets of R specifies a constraint on the possible tuple that can make a relation

Field, examples of fields in a database

examples of fields in a database

Explanation of system architecture of dbms, Q.   With the help of a suitabl...

Q.   With the help of a suitable diagram gives module wise explanation of system architecture of DBMS. Sol. A Database management is a collection of interrelated data and col

Write a short note on built in function in qbe, Write a short note on built...

Write a short note on built in function in QBE? Built in function in QBE: QBE involves various built in functions like AVG, MAX,MIN,SUM and CNT. We must prefix these operator

MANAGEMWNT OF PRINCILES AND TECHNIQUES., HOW TO SOLVE THE LP Problems by si...

HOW TO SOLVE THE LP Problems by simplex method?z=x1+-3x2+2x3

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