Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Serialisable Schedules:If the processes of two transactions conflict with each other, how to verify that no concurrency related problems have happened? For this, serialisability theory has been developed. Serialisability theory attempts to verify the correctness of the schedules. The rule of this theory is:
"A schedule S of n transactions is serialisable if it is equal to some serial schedule of the similar 'n' transactions".
A serial schedule is a schedule in which either transaction T1 is totally done before T2 or transaction T2 is totally done before T1. For instance, the following figure clears the two possible serial schedules of transactions T1 & T2.
Schedule A: T2 followed by T1
Schedule B: T1 followed by T2
Schedule
T1
T2
Read X
Read Y
Subtract 100
Display X+Y
Write X
Add 100
Write Y
Figure: Serial Schedule of two transactions
Schedule C: An Interleaved Schedule
Figure: An Interleaved Schedule
Now, we have to figure out whether this interleaved schedule would be performing read and write in the same order as that of a serial schedule. If it does, then it is equivalent to a serial schedule, otherwise not. In case it is not equivalent to a serial schedule, then it may result in problems due to concurrent transactions.
management information system based on functional organisation
The Update Operations : Update operations are used for altering database values. The constraint violations faced by this operation are logically the similar as the problem faced
i need to submit in this topic.
i need help with creating database system for a library
What is a Transaction? A transaction is an event which happens on the database. Generally a transaction reads a value from the database or writes a value to the database. If y
What are the physical characteristics of magnetic disks? Ans: A magnetic disk is a circular plate or platter of plastic or metal that is coated with magnetizable material lik
Database Administrator One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having li
Introduction In large projects, we can have many different companies working together. Generally, the project or contract is awarded to one company (Principal Contractor), which
What are the two main goals of parallelism? Load -balance multiple small accesses, so that the throughput of such accesses enhances. Parallelize large accesses so that the res
Define entity integrity and referential integrity. How does SQL allow specification of these? Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribut
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd