Electronic Data Processing

1. Electronic Data Processing
(EDP)
Muhammad Zaman-ul-Haq
B-Tech (Civil)/F18, ICTE,IIUI
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2. Managing Files: Basic Concepts
 Data can be grouped into categories
 The data storage hierarchy consists of the
levels of data
 Bits
 Bytes
 Fields
 Records
 Files
 Databases
stored in a computer
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3. Managing Files: Basic Concepts
 Characters: A character (byte) is a letter,
number, or special character
Examples : A, B, C, 1, 2, 3, #, $, %
 Field: A field is a unit of data consisting
one or more characters (bytes).
Examples: your name, address
of
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4. Managing Files: Basic Concepts
 Record: A
fields.
Examples
:
record is a collection of related
Student code, name and
address
 File: A file is a collection of related records.
Examples: file of students grade
information
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5. Managing Files: Basic Concepts
 Database: is an organized collection
related files.
of
Example
s
: Student informatio
n
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6. Managing Files: Basic Concepts
Type of data Contains Example
Database Several files Student database
Address, Grade, Fee
File Several records Name Address
Jack Bangkok
Rocky Chiangmai
Record Several fields Name Address
Jack Bangkok
Field Several Characters Name
Jack
Character Bits (0 or 1) S
1110 0010 8

7. Example from MS-Access
 Student Address File
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8. Types of Files
 File is the collection of data or information
 The user gives
for future use
 The file names
 Example –
a name to each file to save
have an extension name.
 Microsoft
 Microsoft
 Microsoft
Word
Excel
PowerPoint
.doc
.xls
.ppt
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9. Types of Files
 There are many types of files but the
most important
Program files
types are –
Data files
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10. Program Files
 Program files
instructions.
 The program
by a program
are files containing software
files are instruction files written
for a particular application
 They have a file extension. For example –
.bas for BASIC, .pas for Pascal or .jav for Java
 For the processor to use a source file at first it
must be converted to an executable file,
.exe file
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11. Data files
 Data files are files that contain data –
words, numbers, pictures, sounds, etc.
 Data files are created by the users.
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12. Other types of files
 ASCII files
 .txt
 Image(graphic files)
 .bmp, .gif, .jpg, .pcx,
 Audio files
 .wav, .mid, .mp3
 Animation/video files
 .avi, .mpg
 Web files
.tif, .wmf
 .html, .htm, .xml, .php, .asp
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13. Data Access Methods
 Sequential Storage: means
in
that data is
in
stored and retrieved sequence,
alphabetically
order
– ascending or descending
 Example: A tape cassette
 Advantage: less expensive
 Disadvantage: file searching is slow
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14. Data Access Methods
 Direct Access Storage: means that
computer can go directly to
as
the information
you want. It is also known
 Example: A CD Player
 Advantage: faster
random.
 Disadvantage: more expensive
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15. Offline Storage
 Offline storage means that data is not in
the direct control on the CPU. It maybe
saved in a CD.
 The data
device.
has to be loaded onto an input
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16. Online Storage
 Online storage means that data is
immediately accessible by the CPU.
 You need not wait for a CD.
(direct
 Storage is on the disk access storage)
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17. Database Management
DBMS
Systems
 A database is an organized collection
 There are many types of databases
of related files
 To manage the information a database
management system is used
 The DBMS is a program that controls the structure
of a database and access to the data
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18. Advantages of DBMS
 File Sharing
 users can share files
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19. Advantages of DBMS
 Reduced
 prevent
data redundancy
duplication
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20. Advantages of DBMS
 Improved data integrity
 accurate and up to date
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21. Advantages of DBMS
 Increased security
 data can be secured by the use of passwords
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22. Types of Database Access
 Individual database
 used by one person
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23. Types of Database Access
 Shared database
 shared by many people in one location
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24. Types of Database Access
 Distributed database
 shared by many people in many locations
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25. Types of Database Access
 Public databank
 information
 Yahoo
 Google
 Law
 Shopping
 News
 Games
for the public
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