Unrepeatable reads-problems of concurrent transactions, Database Management System

Assignment Help:

Unrepeatable reads: Assume T7 reads X twice during its implementation. If it did not update X itself it could be very disturbing to see a dissimilar value of X in its next read. But this could occur if, among the two read operations, another transaction modifies X.

 

T7

T8

Assumed value of

X=2000

T7

T8

READ X

 

2000

 

 

UPDATE X

 

3000

READ X

 

3000

 

 

Therefore, the inconsistent values are read and results of the transaction may be in fault.

 


Related Discussions:- Unrepeatable reads-problems of concurrent transactions

How to create values of structured type, How to create values of structured...

How to create values of structured type? Constructor functions are used to make values of structured types. A function with the similar name as a structured type is a construct

Explain the five levels of capability maturity models, Question 1 What is ...

Question 1 What is data mining? Write Data Mining applications Question 2 What is OLAP? Write the benefits of OLAP Question 3 What is Business Intelligence? Explai

Hoework, Farmer Bob, Farmer Jane and Farmer Jose run a cow farming co-op. ...

Farmer Bob, Farmer Jane and Farmer Jose run a cow farming co-op. For every cow they keep the cow’s name, age (or date of birth), breed and numbered plastic ear tag. The each of t

Forward recovery (redo), Forward Recovery (Redo): In this system the commit...

Forward Recovery (Redo): In this system the committed changes made by a transaction are reapplied to a previous copy of the database.                          In simpler

Write short notes on extension and intension, Write short notes on extensio...

Write short notes on extension and intension? In any data model, it is significant to distinguish among the description of the database and the database itself the description

Which component is not included in database environment, Which component is...

Which component is not included in database environment ? A users component is not included in database environment.

Appointment systems with sms and voice call feedback, Automated system for ...

Automated system for appointment with sms and call confirmation with service providers and user has to be initiate automatically. After selecting time and date to use service, s

Explain interfaces for parametric users, Explain Interfaces for parametric ...

Explain Interfaces for parametric Users? Interfaces for Parametric Users - Parametric users, such as bank tellers, frequent have a little set of operations in which they must p

Information system fundamentals, A full discription of the new, a discripti...

A full discription of the new, a discription of its components, and the bebefit it will provide a company. A disscussion of the information usedin the system. A disscussion of any

Query optimization, what is meant semantic query optimization? how does it ...

what is meant semantic query optimization? how does it differ from other query optimization techniques?

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