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!
Explain Two phase locking protocol
A transaction is consider as to follow the two-phase locking protocol if all locking operations precede the first unlock operation in the transaction. Such type of transaction can be divided into two phases: and expanding or growing (first) phase, throughout which new locks on items can be acquired but none can be released; and a shrinking (second) phase, throughout which existing locks can be released but no new locks can be obtained. This two-phase protocol can make sure the serializability because all the data items needed by a transaction will be locked at the starting of the transaction and if other transaction needs to use those data items then it has to wait till they become unlocked.
What are the uses of the information in the Data dictionary? The following information is directly taken from the Data dictionary: Information on fields displayed with
Data Definition Language It organises the data in the form of columns and rows. But what does the data field column of table accumulate? How do you describe it using SQL? Th
What is a SELECT operation? The select operation selects tuples that please a given predicate. We use the lowercase letter σ to denote selection.
Question: Consider the following database relations for a textbook ordering system used by a college bookshop: Book (b-copy#, bname, ISBN#, author, price, subject) Order (s#
Give some encryption techniques? A) DES B) AES C) Public key encryption
What are the three types of data sources used with ODBC? An ODBC file data source is a file that can be shared between database users. An ODBC system data source is one that is
(a) What is a Sub-Query? (b) What is the difference between a scalar sub-query and a tabular sub-query? (c) Write an equivalent SQL statement to get the Name of Product wh
One-way Associations If an association is only traversed in single direction, then it is known as one-way association. It is implemented as a pointer or an attribute which con
Illustrate the statement 'Projection operation distributes over the union operation'. Give an example. Ans: Π L (E 1 ∪ E 2 ) = (Π L (E 1 )) ∪ (Π L (E 2 )) This says th
Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o
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