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

Describe the strategies adopted by the ministry of ict, Question 1: (a)...

Question 1: (a) Planning and management of ICT projects have a very poor record in developing countries. Briefly explain five critical success factors for correct implementa

What is the state machine engine, What is the State Machine Engine The...

What is the State Machine Engine The straightest approach to implement control is to have any way of explicitly representing and executing state machines. With the help of thi

Online examination system project, entity relationship diagram for online e...

entity relationship diagram for online examination system

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Create a new service-based database, In this assignment, you will create a ...

In this assignment, you will create a program that works with multiple tables. In this assignment, you will work with the factory and sales tables. 1. Create a new project nam

Define hash files organization, Define Hash files organization a. Hashi...

Define Hash files organization a. Hashing includes computing the address of a data item by calculating a function on the search key value.   b. A hash function h is a functi

Create the logical database schema, 1.  Based on the dependency diagram, cr...

1.  Based on the dependency diagram, create a database whose tables are in at least 2NF, showing the dependency diagram for each table (as shown in class).  Label the types of depe

Explain discretionary access control, Problem: (a) Given the following ...

Problem: (a) Given the following relation: Stats(Name,Sex,Children, Occupation, Salary, Tax, Audits) Write SQL code to define the following security constraints: (i) User

What is predictive modelling, Problem: (a) Data mining is one of the b...

Problem: (a) Data mining is one of the best ways to analyse data and using software techniques, hidden and unexpected patterns and relationships in sets of data can be extrac

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