What is a transaction? , Database Management System

Assignment Help:

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:


Related Discussions:- What is a transaction?

Exclusive lock, Exclusive lock It is asked for by a transaction on...

Exclusive lock It is asked for by a transaction on a data item that it wants to update. No other transaction can put either a shared lock or an exclusive lock on a dat

Memory components of sga, Problem 1. Describe the Oracle Architecture w...

Problem 1. Describe the Oracle Architecture with a neat labeled diagram, Also explain the individual components of the Architecture. 2. Write about the following Oracle 9i o

Entity identifier key attributes, An entity type usually has an attribute w...

An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be

Query processor in database management system, Query Processor The qu...

Query Processor The query language processor is responsible for taking query language statements or shifting them from the English-like syntax of the query language to a form

What is called as an n-way merge, What is called as an N-way merge? The...

What is called as an N-way merge? The merge operation is a generalization of the two-way merge used by the standard in-memory sort-merge algorithm. It merges N runs, so it is k

Database, real life situations where database management system are most su...

real life situations where database management system are most suitable

Examine about the behavioural diagrams, Examine about the Behavioural Diagr...

Examine about the Behavioural Diagrams  The main objective of behavioural diagrams is to visualize, specify, construct and document dynamic aspects of a system. The interactio

In which form of relational database developer refers, In which form of rel...

In which form of relational database developer refers to a record? In a tuple form of relational database developer refers to a record.

ERD, #question.ERD of any car

#question.ERD of any car

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd