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

Database ass1, #quCreate a database design specification (Enhanced Entity R...

#quCreate a database design specification (Enhanced Entity Relationship Diagram (EERD) and Relational Data Model (RDM)) from the given business description. The RDM must be in 3rd

Explain p command in the respect of qbe, Explain P command in the respect o...

Explain P command in the respect of QBE? P: It is the command in which is used to print (logically display) the value of the attribute in whose cell it is writ

What is substitutability, What is substitutability? Any method of a cla...

What is substitutability? Any method of a class-say A can equally well be adjured with any object belonging to any subclasses B of A. This characteristic leads to code reuse, a

Indexed (indexed sequential) file organisation, Indexed (Indexed Sequential...

Indexed (Indexed Sequential) File Organisation It organises the file like a big dictionary, i.e., records are kept in order of the key but an index is stored which also allows

Requirements for your cache simulator, Using your cache simulator and using...

Using your cache simulator and using smalltex.din as your memory trace determine the total miss rate, compulsory miss rate, capacity miss rate, and conflict miss rate for the follo

Define object oriented model, Object Oriented model :An object has values...

Object Oriented model :An object has values stored in instance variables within the object. An object also has bodies of code that execute on the object. These bodies of code are

Unix System Administration, What Command You Use What Day of the week were ...

What Command You Use What Day of the week were you born

Bid Cunt, How do I use strap on?#

How do I use strap on?#

What does conceptual design work, What does conceptual design work? A c...

What does conceptual design work? A conceptual design involves modelling independent of the DBMS.

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.

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