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7/29/2019 Computer Processing Techniques
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Computer Processing Techniques
UNIT 1
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DATA V/s INFORMATION
DATA INFORMATION
Raw facts or figures Finished one
Unstructured Structured
Unprocessed data Processed data
What exists What is required
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Data Processing
It is the conversion of data into more useful form i.e.transmission of data into meaningful information.
Simplified Version
INPUTData
PROCESSING
OUTPUTInformation
Detailed Version
DATARecord,
checked
andprepared
InputPROCESSIN
GBy computer
MAINTAINED DATAe.g. permanent
details of employees
Informatione.g. Pay slips
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Kinds of data processing
1. Manual data processing abacus, slide rule, Napier
bones
2. Mechanical data processing
Electromechanicaldevices such as calculators, tabulators.
3. Electronic data processing Using systems
Objectives of data processing
Handle data
Qualitative and quantitative data
Appropriate and timely information Helps in decision making
Improving productivity
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Steps Of Data Processing
1. Preparation of source documents
2. Input of data
3. Manipulation of data (shifting, sorting and rearranging
the given input)
4. Output of information
5. Storage of information
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DATA BASE
It is the huge reservoir of data.
Data base is an organized collection of files of
information that has been systematically recorded
and may form the basis of a computer memory and
designed for easy access by authorized users.
Database Management System (DBMS)
It is a system for operating the data base
The system or set of rules and methods allows for
the definition, creation, updation, reading,
maintenance and protection of the data base.
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Methods /Modes Of Data Processing
1. Single User System
2. Batch Processing
3. Multi-Programming
4. On-Line Processing
5. Real Time Processing
6. Time Sharing
7. Distributed Processing
8. Multi-Processing
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1. Single User System
It indicative of one of the earlier stages of
computer development.
Here only one person can work at a time.
If the system is meant for the use of many
persons, much time is wasted waiting for one
person to finish his program
COMPUTER 1
USER 1 USER 2
COMPUTER 2
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2. Batch Processing
It is an old system but it is still for processing in
which the capacity of the C.P.U is limited.
Here the data is collected and accumulated into
batches and processed periodically
Here emphasis is on maximizing the computer
resource utilization.
Jobs are processed one after the other without
any user interaction.
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e.g. Telephone billing: Here the subscriber does not
get bill for every call he makes. Instead, his calls are
recorded at a centralized place and are processed on
a predetermined period of time to prepare his bills.
Drawbacks
Time gap between capture of data
Time consuming
Delay in generating reports
Stores Dept
Transaction
Data preparation
Punch cards
COMPUTER
REPORTS
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3. Multi-programming / Multi tasking
In batch processing the memory and ALU are not
fully utilized.
Multi-programming enables to store execute more
than one program in the C.P.U at the same time.
When I/O devices are performing certain tasks the
C.P.U may not be doing any task, it may be lying
idle so it is desirable to process a number of
programs concurrently. This is achieved by
overlapping the C.P.U & I/O operations when several
programs are running simultaneously.
Improvement over batch processing. It does not
allow users to interact with the computers
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INPUT OUTPUTPROGRAM 1
PROGRAM 2
PROGRAM 3
Processing
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4. Multi-Processing
Multiprocessing systems have 2 or more CPU which
have the ability to execute two or more jobssimultaneously.
Instructions from several programs are carried out by
different CPUs at the same time.
When one CPU fails then the other takes over the
processing
In some other, networks are formed by interconnecting
the CPUs , the small CPU called front end processors
are used for I/O operations, scheduling, controlling of
jobs. In some each CPU perform only specific type of
Ad
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Advantages
More efficient use of hardware resource other than
cpu.
High reliability is ensured by the provision of automatic
take over of complete work by other CPU in case of
break down
Disadvantages
Large memory is required as it require many data and
programs in memory at any time
Very expensive as it incur high operation and
maintenance cost
It requires highly sophisticated operating system
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5. On-Line Processing
Here data is not accumulated, instead data it is
entered and executed directly. Data is transmitted between I/O devices and a
computer system via communication links.
Here many users have direct access to the same
system and the file updated as soon as the
transaction is completed
The online system consist of a large computer
connected to many online terminals which
communicate with it.
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Here the system interacts directly with the user.
Records are updated at any time whereas in batch
processing updating may be once in a week.
E.g.
Banking : It is possible to inform bank customers of
the status of their accounts in response to an enquiry by
accessing relevant file using online terminal.
Benefits
Reduction in paper work
Improved accuracy
File updating
Easy access to file
Improved customer service
6 R l Ti P i
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6. Real Time Processing
Also called Interactive mode or direct mode
It is called a real system because it has to give
results based on dead lines which are imposed.
User can have direct contact with the computer
through his terminal.
Data is processed on the spot and no delay
between the time data is available and the time it
is processed.
It is the technique of updating files, transactions,
data immediately after the event to which it
occurs.
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Suitable for business operations such as
Wholesale supplier & manufacturer Airline seat availability
Manufacturing
Terminal1
Terminal4
Terminal3
Terminal2
Computer
Data
7 Ti Sh i / M lti t
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7. Time Sharing / Multiuser system
It allow each user to interact with the computer.
Individual user has an independent terminal
connected to the main computer which does all the
processing work.
The processor time is shared between two or more
persons
The processor switches from one users job to
another at a rapid rate under the control of a
monitor program.
This concept is time based. All the users have the
same priority so they get equal amount of
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User 1
User 2
User 3
User 4
HOST COMPUTERTIME 1 USER 1TIME 2 USER2TIME 3 USER3TIME4 USER4
TIME5 USER1TIME 6 USER2
8 Di ib d P i
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8 .Distributed Processing
It is a network of several computers in remote stations, each
of which is linked to a single host of computer. Processing
power is distributed among several locations
Larger computer central computer maintains the firms
master data base.
Each system is fully independent computer that maintains its
own local data base in addition to communication with the
master computer. All these systems are tied together to a
high speed communication network
E.g. In the retail industry, each stores network does its own
processing but is under the centralized control of the stores
head quarters
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Advantages
Accessing unused processing power
Distance and location is not a barrier
The system is more responsive to the local needs
Resources can be shared
Computer power can be added or removed according
to the needs
Disadvantages
Dependence on communication technology
Incompatibility between equipments
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Transaction Processing
A transaction is an update made to information in a
database
In electronic data processing data is processed in the
computers automatically. Transactions are carried out
automatically through computers and its known as
Transaction processing systems. These systems
supports day to day operations.
Payroll, inventory are some of the transaction
processing systems
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Types Of Transaction Processing System
Online Transaction Processing
This is the direct communication method between the
operator and the transaction program. It will provide
immediate results. Here transactions are processed to
update a file or to make modifications in a file after the
transactions occur.
Batch Transaction Processing
Transactions are grouped together & processed
periodically on a sequential basis.