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

Discuss the problem of spurious tuples, Discuss the problem of Spurious tup...

Discuss the problem of Spurious tuples and how we may prevent it.    Ans:  A spurious tuple is, mainly, a record in a database that gets created while two tables are joined bad

Dml precompiler in database management system, DML Precompiler All th...

DML Precompiler All the DBMS have two basic sets of Languages - Data Definition Language (DDL) that have the set of commands needed to define the format of the data that is b

Explain the functional mode with help of an example, Explain the Functional...

Explain the Functional Mode with help of an example. Functional Model  The functional model shows a computation and functional derivation of data values in it without ind

Clinic, Need a sample of a clinic database relationships

Need a sample of a clinic database relationships

What are the responsibility of file manager, What are the responsibility of...

What are the responsibility of File manager? File Manager : Manager allocation of space on disk storage and the data structures used to represent within stored on disk. It is a

Three levels of ANSI-SPARC architecture, a need some real life examples of...

a need some real life examples of database management systems three level of ANSI SPARC architecture life teacher and student ,company and employee or for NGO etc.

Explain the components of database system in details., Explain the compone...

Explain the components of Database System in details.

Explain tuple variable, Define tuple variable? Tuple variables are used...

Define tuple variable? Tuple variables are used for comparing two tuples in the same relation. The tuple variables are explained in the from clause by way of the as clause.

Guidelines for creation of table, Guidelines for creation of table: ...

Guidelines for creation of table: Table name should begin with an alphabet. In table name, single quotes and blank spaces are not allowed. Reserve words of that DBM

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