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!
Strict 2PL:Though, this basic 2PL suffers from the trouble that it can result into loss of isolation / atomic property of transaction as theoretically speaking once a lock is released on a data item it can be changed by another transaction before the first transaction aborts or commits.
To leave such a situation we use strict two phase locking. The strict 2PL is graphically depicted in Figure. Though, the basic drawbacks of strict 2PL are that it restricts concurrency as it locks the item afar the time it is required by a transaction.
Figure: Strict Two Phase Locking
Does the two phase locking solve all the problems of concurrent transactions? No, the strict 2PL answers the problem of concurrency and atomicity, though it introduces another problem.
Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,
What do you mean by Correlated subquery? Subqueries, or nested queries, are used to bring back a set of rows to be used by the parent query. Depending on how the subquery is writ
Multilevel Index The Multilevel Index is a modification of the secondary level index system. In this system we might be use even more number of levels in case the table is eve
Describe the nested-loop join and block-nested loop join. Ans: The block nested- loop join algorithm is as described below: for every block B r of relation R do beg
When every condition appears with equality condition (=) only. c) Natural join (denoted by R*S) When two join attributes have the similar name in both relations. (Tha
(a) Provide the description of the following ODMG schema in the Object Definition Language (ODL). (b) Based on the above object database, write the following queries i
If R1 and R2 are two union compatible relations or functions, then the result of R3 = R1 ∩R2 is the relation that contains all tuples that are in both the relations In other words,
I have a homework assignment due today by midnight. I need help understanding databasse normalization and determining the type of form violation & how to fix the violation.
Explain group By clause in SQL? Group By clause in SQL: The GROUP BY clause can be used in a SELECT statement to collect data across multiple records and group the results thro
Explain Transaction manager and their work? Transaction Manager: Ensure the database remains in a constant (correct) state despite system failure, and in which concurrent trans
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