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!
What is a transaction?
The Transaction is a unit of data processing. For instance, many of the transactions at a bank may be withdrawal or deposit of money; transfer of money from A's account to B's account etc. A transaction would include manipulation of one or more data values in a database. Therefore, it may need reading and writing of database value. For instance, the withdrawal transactions can be written in pseudo code as:
Example:
; Suppose that we are doing this transaction for person
; whose account number is X.
TRANSACTION WITHDRAWAL (withdrawal_amount)
start transaction
IF X exist then
READ X.balance
IF X.balance > withdrawal_amount THEN
SUBTRACT withdrawal_amount
WRITE X.balance
COMMIT
ELSE
DISPLAY "TRANSACTION CANNOT BE PROCESSED"
ELSE DISPLAY "ACCOUNT X DOES NOT EXIST"
End transaction;
Another same example may be transmitting of money from Account no x to account number y. This transaction may be written as:
Determine the benefits of Object oriented design OOD also gives reusability, which saves time, costs and productivity gains through direct mapping to properties of Object-Orie
What was the method in which records are physically stored in a specified order according to a key field in each record ? A method in which records are physically stored within
Differentiate between natural join and outer join? Natural join is a binary operator which is written as (R * S) where as R and S are relations. The output of the natural join
Assigning Responsibility for Operation Many operations might have obvious target objects, but some of these operations could be used at numerous places in an algorithm, by one
Describe file organisation? A file is organized logically as a sequence of records. These records are mapped onto disk blocks. A) Fixed-Length Records Type deposit=record
Redo Logs: Any database must have minimum two redo logs. These are the rules for the database; the redo logs record all modifies to the system objects or user objects. If any type
Explain CNT in the respects of QBE ? CNT: It is one of the aggregation commands given in QBE. It is used to identify number of tuples
Difference between LEFT OUTER JOIN and RIGHT OUTER JOIN In left outer join tuples from the left-hand-side relation which do not match any tuple in the right-hand-side relation
Replication : It is definite as a copy of a relation. Every replica is stored at a dissimilar site. The alternative to replication is to store only single copy of a relation which
When is a transaction rolled back? Any changes that the aborted transaction made to the database must be uncompleted. While the changes caused by an aborted transaction have be
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