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.
What is the main advantage of the object model? What are its different components? The object model focuses on the logical data structures. Each object model comprises of many
I am doing research in this area, especially in sime join and join efficacy when several relations have been queried. Relations located in different sites. I need something like n
What is the role of ORDER By Clause? ORDER BY clause: The ORDER BY clause permits you to sort the records in your result set. The ORDER BY clause can just be used in select s
In case of entity integrity, the primary key may be declared? In a case of entity integrity primary key may be not Null.
how to design tables
Determine the method of Choosing Algorithms In general, most of operations are easy and have a satisfactory algorithm since description of what is to be done also shows how i
Give the forms of triggers? The triggering event can be insert or delete. For updated the trigger can state columns. The referencing old row as clause The referencing
1. Explain different addressing modes of 8086 Explanation of all addressing modes 2. Write a sequence of instructions to exchange two register contents using stack
Set Difference If R1 and R2 are two union compatible relations or relations then result of R3 =R1- R2 is the relation that have only those tuples that are in R1 but not in R2.
If R1 and R2 are two relations or functions, then the result of R3 = R1 × R2 is the combination of tuples that are in R1 and R2. The product is associative and commutative. Degr
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