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?

Implementing a data warehouse, (a) Data warehouse can be defined as "a sub...

(a) Data warehouse can be defined as "a subject-oriented, integrated, time-variant, non-volatile collection of data" in support of management's decision making process. Explain ea

Construct substantial data model, PART MARKING:  We will only mark TWO of t...

PART MARKING:  We will only mark TWO of the four questions below but you must submit answers to all four. We will choose the questions we mark randomly and we will supply you with

What is oracle databse structure, What is Oracle databse structure? Or...

What is Oracle databse structure? Oracle database structure: The relational model has three main aspects: Structures: Structures are well-defined objects which store th

Oracle, I have 10+ yrs exp in oracle Sql ,Pl/SQl,Forms ,Reports. I am exper...

I have 10+ yrs exp in oracle Sql ,Pl/SQl,Forms ,Reports. I am expert in assignements & Online tutoring so i want to join you. Please guide me. Thanks Brajesh Shukla +91 9899641535

Idea for fyp, want a idea for final year project

want a idea for final year project

Where does view definition stored, Where does view definition stored? ...

Where does view definition stored? A view definition is permanently stored as part of the database.

Er schema, Consider entity type Employee with attributes empNumber (this is...

Consider entity type Employee with attributes empNumber (this is unique), empName, and the year when he/she was hired. An employee can either be a technical employee, a marketing e

Reflects organisational structure, Reflects organisational structure: Many ...

Reflects organisational structure: Many organizations are distributed over various locations. If an organisation has many offices in dissimilar cities, databases used in such an ap

Data manipulation language, Data Manipulation Language Data manipulatio...

Data Manipulation Language Data manipulation language (DML) describes a set of commands that are used to query and change data within existing schema objects. In this case comm

Keys, #questiontypes of keys examples..

#questiontypes of keys examples..

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