Transcript Transaction Processing Systems

Transaction Processing Systems
Defining a TPS

A TPS collects, stores, modifies and
retrieves the transactions of an
organisation
Characteristics of a TPS
Rapid response – fast performance with
rapid results
 Reliability – well designed backup and
recovery with a low failure rate
 Inflexibility – treat every transaction
equally
 Controlled processing – maintain
specific requirements for the roles and
responsibilities of different employees.
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Batch Processing in a TPS
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Batch transaction
processing collects
the transaction data
as a group (batch)
and processes it at a
later time eg cheque
clearance or
generating pay
cheques.
Real-Time Processing in a
TPS
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Real-time transaction
processing is the immediate
processing of data eg-airline
reservation systems or
banking transaction systems
Transaction processing monitor

A TP monitor is software that provides a
standard interface between the input
devices, the transaction processing
application programs and the DBMS. It
also provides data security and is an
important part of real-time processing.
Real-Time vs. Batch
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Real-time:
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Each transaction is unique
Requires master file to be
readily available
Has fewer errors as data is
entered and validated
immediately
More computer operators
required
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Batch:
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Cheaper
Transactions
must have similar
inputs and
outputs
Any error is not
immediately
detected
Easier to maintain
Less IT required
Data validation
Involves procedures to ensure that
transactions are correct and have been
accurately stored in the database
 Although essential, it is impossible to
validate all the data as some errors are
very difficult to detect eg typing ‘1986’
instead of ‘1987’
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Manual transactions
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Manual transaction systems are business systems
which operate without an information system (i.e.
no computers). They have been around for
thousands of years. The earliest writings are
Sumerian business receipts on clay tablets which
are around 5 thousand years old. But of course
people still keep manual transaction records.
Manual transactions
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You probably keep receipts for goods that you
buy. You may keep these for tax reasons or for
warranties but either way they are transaction
records
Until recent times many records were still stored in
account books. This required bookkeepers to balance
the accounts -These are the manual equivalent of
spreadsheets
Manual Transactions
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Transferring paper based records into an
electronic system has many benefits including:
customers can purchase goods at their
convenience
it is easy to do stock takes
reduced wage costs
Whatever the peripheral benefits
computerization of a manual system will aim to
maximize profits.
Manual Transaction Systems
A manual transaction system is a business
system that operates without the use of
machines
 People record the data and perform stock
takes to check for misplaced/stolen money or
stock
 Computerisation provides significant benefits
as it is faster, more affective and provides
relevant information for the business.
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Components of a TPS
Users – a main feature of a
TPS, they often take the
data provided by it and use
it in another information
system
 Participants - people who
conduct the information
processing, success or
failure is dependant on
them
 People from the environment become participants when
they directly enter transactions and perform validation eg
withdrawing money from an ATM
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Examples of TPSs
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Real-Time
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Reservation
systems
POS terminals
Library loan
systems
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Batch
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Cheque clearance
Bill generation
Credit card sales
and transactions
Storing and Retrieving – Databases
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A database is an organised collection of data.
There are three structures:
Hierarchical
Network
Relational
Important Database Features
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Real-time TPS databases should have:
Good data placement
 Short transactions
 Real-time backup
 High normalisation
 Archiving of historical data
 Good hardware configuration
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File Types in a TPS
Master file
 Transaction file
 Report file
 Work file
 Program file
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Data Warehousing
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A data warehouse is a database that
collects information from different data
sources. Data has to be:
Consolidated
 Subject-oriented
 Historical
 Read-only
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Backup and Recovery
A backup is another copy of data that
could be used to rebuild the system, if
failure occur
 Recovery of a database involves:
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The backup
 Journal
 Checkpoint
 Recovery manager
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Grandfather-Father-Son
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A backup procedure that refers to at least three
generations of backup master files
Commonly used with magnetic tape
If the TPS fails, the first generation backup is used
(son) to recover it, if this is also corrupted the next
generation is used (father) and so on
Updating data
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In a batch:
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Involves sequential
access
Most common
medium is magnetic
tape
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Real-time
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Involves direct
access
Can be stored on
magnetic disk, CD,
hard disk and others
Collecting data in a TPS
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Hardware
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MICR (magnetic ink character recognition)
ATM
Barcode readers
Forms
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On-screen forms
Web forms
Analysing data from a TPS
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Done as input in other information systems
including:
DSSs, decision support systems
 MISs, management information systems
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Issues Related to TPSs
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Nature of work is changing
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Automation of jobs
People as participants
Bias free data
 Data security
 Data accuracy
 Data integrity (the ACID test)
The ACID Test
Atomicity – all steps involved in a
transaction are completed as a group
 Consistency – database is successfully
transformed from one state to another
 Isolation – simultaneous transactions
don’t interfere with each other’s database
updates
 Durability – all changes to the database
are permanent when the transaction is
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Collecting data
Bar-code readers
 EFT- POS devices
 Cash registers
 Web forms
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Organising
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DBMS – sort and
organise all the data
from the
transactions from
the internet,
different terminals
and stores
Analysing
DSS – using data mining to determine
relationships and patterns in product sales
at stores
 MIS – assist managers in generating stock
inventories, payrolls, orders and budgets.
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Storing and Retrieving
Data should be stored on-site with
backups both on-site at each store as
well as off-site at the head office
mainframe computer
 Hard disks, floppy disks, CDs and/or
other storage media should be used
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Processing
Backups should be done using the
grandfather-father-son method updated
at least two times per day
 Transaction journals should be kept for
web sales as well as each terminal for
system recovery and to track down any
missing or stolen money.
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Transmitting and Receiving
Each terminal at each store should be
connected to the mainframe in that store
in a LAN
 Each mainframe at each store should be
connected to the mainframe at the head
office as well as the internet for web
transactions in a secure WAN
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Displaying
Each terminal needs a printing device for
customer receipts
 A user-friendly web interface for internet
transactions
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Implementation
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A new system can be implemented in
several different ways:
Direct conversion
Old
New
Parallel conversion
Old
New
Phased conversion
New
Old
Pilot conversion
Old
Old
Old
New
New
New
Social and Ethical Issues
Every customer has a right to their own
privacy and details stored such as credit
card number, name and address have to
be secure
 The implementation of a new TPS would
require staff to be skilled in different areas
 Transaction data has to be secure during
transmission to the mainframe as well as
while stored
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Transaction Processing system
QUIZ
1. Which of these is not an important
characteristic of a TPS
a)
b)
c)
d)
Reliability
Rapid response
Flexibility
Controlled processing
2. Real-time processing is:
a)
b)
c)
d)
Cheaper than batch
Faster than batch
Not real at all
Used in bill generation
3. Which of the following is not a
component of a TPS:
a)
b)
c)
d)
Users
Participants
People from environment
Data mining
4. Which is not an example of a
TPS:
a)
b)
c)
d)
POS terminal
Airline reservation system
Library loan system
E-mail
5. In a manual transaction system:
a)
b)
c)
d)
People record the data and perform
stock takes
Robotic arms perform manual labour
People operate computers and
machinery
There is no data
6. The five basic file types in a TPS
are:
a)
b)
c)
d)
Master file, slave file, teacher file, child
file and print file
Terminal file, processing file, master
file, slave file and backup file
JPEG, GIF, PGF, PNG and PSD
Master file, transaction file, report file,
work file and program file
7. The ACID test involves:
a)
b)
c)
d)
The Atomic Composition of Information
Databases
Testing the chemical properties of
storage media in TPSs against
sulphuric acid
The Atomicity, Concurrency, Isolation
and Dataframe
The Atomicity, Consistency, Isolation
and Durability
9. Recovery of a database involves:
a)
b)
c)
d)
The backup, journal, TP monitor and
operating system
The backup, journal, checkpoint and
recovery manager
Travelling back in time to a point where
the database was functional
The storage of backups off-site
ANSWER
10. Which of these is not a database
structure:
a)
b)
c)
d)
Relational
Hierarchical
Architectural
Network