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!
"Wound-wait" scheme: It is based on a preemptive method. It is based on a simple rule:
If Ti requests a database resource that is held by Tj
then if Ti has a larger timestamp (Ti is younger) than that of Tj
it is allowed to wait;
else Tj is wounded up by Ti.
For example, suppose that 3 transactions T1, T2 and T3 were generated in that series, then if T1requests for a data item which is presently held by transaction T2, then T2 is rolled back and data item is allotted to T1 as T1 has a smaller time stamping than that of T2. Though, if T3 requests for a data item which is presently held by transaction T2, then T3 is permitted to wait.
Figure: Wound-wait Scheme of Deadlock prevention
It is vital to see that whenever any transaction is rolled back, it would not make a starvation condition, i.e., no transaction gets rolled back repeatedly and is never permitted to make progress. Also both "wait-die" & "wound-wait" idea avoid starvation. The number of aborts & rollbacks will be higher in wait-die scheme than in the wound-wait idea. But one main problem with both of these ideas is that these ideas may result in unnecessary rollbacks.
Define the Canonical cover Ans: A canonical cover F c for F is a set of dependencies like F logically implies all dependencies in F c , and F c logically entails all dependen
How can i turn a conceptual entity relationship diagram into a logical entity relationship diagram? what do i have to do with "mandetory or" and "optional or" relationships?
Consider a table student (std_id, std_name, date_of_birth, percent_marks, dept_name). Write a QBE query to display names of Computer Science department students who have scored mo
Question: (a) Prepare an ERD for the scenario given below. (b) Convert the ER diagram produced in (a) above into its physical design. You have to choose an appropriate Pri
Describe the four main ways of optimising disk block access. Ans: a. Disk b. Non-volatile writes buffers c. File organization (Clustering) d. Log-based file system
a) Distinguish between ‘database' and ‘Database Management Systems (DBMS)'. b) List and briefly describe five potential benefits of the database approach compared to conventio
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
er diagtram for icici
Determine the Advanced modeling concepts You have to follow some steps for object-oriented design. These steps for OO Design methodology are as follow: 1) Produce objec
What are referential integrity constraints? A value that appears in single relation for a given set of attributes also appears for a particular set of attributes in another rel
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