Introduction to Data Processing

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Introduction to Data Processing
Data vs. Information Data
Representations facts about various events that
affect a business. Information
Data presented in its proper context. Process
Manipulation data with a program. ??????
?????????? ???????????? (facts) ?????????
(figures) ???? ????? ??. ??????????????????
??????? ????????
?????????????????????????????????????? (Data
processing) ??????????????????????????
?????????????????
2
Introduction to Data Processing
Data
Data Processing
Information
- Manual - Computerize - Knowledge
3
????????????????????????????????????????? ???????
??????????????????? ??????????????????? ??????????
???????????????????????? ???????????????? ????????
?????????????????????????????????? ?????? 1.
?????????????? ( Creating ) 2.
????????????????????????? ( Classifying ) 3.
??????????? ( Sorting ) 4. ???????? (
Calculating ) 5. ??????? ( Summarizing )
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6. ?????????????????? ( Storing ) 7.
?????????????????????????????? ( Retrieving ) 8.
??????????????????????????? ( Reproducting ) 9.
???????????????? ( Data communicating )
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?????????????????????? - Input activity of
capturing and gathering of raw
data - Processing converting and
transforming data into information -
Output producing an useful information -
Feedback output that used to make
adjustments or changes to input and
processing activities - Computerized Information
System ?????? ??????????????????????????????
???????
6
?????????????????????????
- ????????????????? (relevant) - ???????
(economical) - ??????? (accurate) -
???????????????? (simple) - ??????? (timely) -
???????? (flexible) - ??????? (complete) -
?????????? (verifiable) - ??????????? (reliable)
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???????????????????????????? ??????????? 3 ????
??? 1. ?????????????????? ( Manual Data
Processing ) 2. ?????????????????????????????
??????????????? ( Manual with Machine
Assistance Data Processing ) 3.
????????????????????????????????????? (
Electronic Data Processing ) ?????????????????????
??????????????????????????????????????? 1.
?????????????????????????? 2.
???????????????? ??? 3. ?????????????????????
?????????? 4. ???????????????????????????????
??????? 5. ??????????
8
Data Organization (???????????????????) ?????????
????????????????????????? ???????????
??????????????????????????????? ???? 4 ?????
????????? 1. ?????????? ( Data Item or Field
) 2. ??????? ( Record ) 3. ?????????? ( File
) 4. ????????? ( Data Base )
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
File Organization Terms and Concepts

• Bit Smallest unit of data binary digit (0,1)
• Byte Group of bits that represents a single
  character
• Field Group of words or a complete number

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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
File Organization Terms and Concepts

• Record Group of related fields
• File Group of records of same type
• Database Group of related files

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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Data Hierarchy in a Computer System
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
File Organization Terms and Concepts

• Entity Person, place, thing, event about which
  information is maintained
• Attribute Description of a particular entity
• Key field Identifier field used to retrieve,
  update, sort a record

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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Entitities and Attributes
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Traditional File Processing
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Problems with the Traditional File Environment

• Data redundancy
• Program-Data dependence
• Lack of flexibility
• Poor security
• Lack of data-sharing and availability

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DATA REDUNDANCY

• The presence of duplicate data in multiple data
  files
• Different functions collect the same information
  independently
• May have different meanings in different parts of
  the organisation

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Data Redundancy
7
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Program Data Dependence

• The tight relationship between data stored in
  files and the specific programs required to
  update and maintain those files
• Every program must describe the nature
• In traditional file environment any changes to
  data requires a change in all programs that
  access the data
• A change in tax rates for example !!

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Lack of Flexibility

• Traditional File system can deliver routine
  scheduled reports after a significant programming
  efforts
• An ad hoc/ unanticipated request for information,
  would require a lot of time
• The information is somewhere in the system but
  too expensive to locate/retrieve
• Compiling the data could take weeks

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Poor Security

• There is little or no control and management of
  data
• Data could be disseminated all over the
  organisation without control
• Who is accessing the data and making changes?

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Lack of Data-sharing

• Lack of control over access
• Hard to get hands on information
• Different pieces of information in different
  files and different physical locations
• Since files in different locations cant be
  related hard to share or access in a timely
  manner
• Impossible for information to flow freely

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Data Base
.......
File
File
File
.......
Record
Record
Record
.......
Item
Item
Item
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File ???????????????????????????? (Records)
????????? ??????????? ????????????????????????????
??????????? ?????????? ???????? (Single format)
???????????????????? (Multiple format) ?????
??????????????????????????????????????????????? ??
??????????????????????????????????????????????????
?????????? ?????????????????????? ????????
4003001 ?????? ???????? 1 A 0.00 0.00 4003002
?.?.???? ?????? 1 B 0.00 0.00 3903001 ??????
???????? 2 A 38.00 76.00 3903002
?.?.???? ???????? 2 B 38.00 85.00
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???????? 4003002 ?.?.???? ?????? 1 B 0.00 0.00 MT
H161 B 1 CHM101 C 1 LNG102 B 0 3903001 ??????
???????? 2 A 38.00 76.00 MTH261
A 1 MTH241 C 0 ??????????????????????????????????
???????? 1. ?????????????????????????????????????
????????? (Memory) ???????????? 2.
??????????????????? ????????????????????? ????????
???? ????????????????????????????????????????????
???
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????????????????????????????????????????????? ???
?????????????? ???????????? 5 ?????? ??? 1.
?????????????? ( Master File ) 2.
??????????????????????????? (
Transaction File ) 3. ???????????????? ( Report
File ) 4. ??????????????????? ( Work File ) 5.
????????????????? ( Program File )
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?????????????????????? (File Operation) ?????????
???????????????????????????????
????????????? ??????????????????????????????? (
File Organization ) ??? ??????????????
??????????????? 2 ?????? ??? 1.
??????????????? 2. ???????????????????????????? ?
?????????????? ???????????????????????? 2 ???
??? 1. ???????? ( Batch ) 2. ????????? (
Interactive )
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?????????? ?????????
?????????? ?????????????????
??????? Update
?????????? ????????? ??????????
???????????? ???????????
?????????????????????????
???????????????????
?????? ?????????
28
??????????
????????????
????????????????????????
?????????? ????????????
?????????? ???????????
????????????????????
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???????????????????????????? ????????????????????
?????????????? 4 ?????? ??? 1. ???????? (
Creation ) 2. ???????????????? ( Updating ) 3.
???????????? ( Retrieval ) 4. ????????????? (
Maintenance ) - ??????????????????????? (
Restructuring ) - ????????????????????????????
?? ( Reorganization )
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???????????????? ( File Organization
) ??????????????????????????????????????????? ???
???????????????????? ????????????????????????????
???????????? 3 ??? ??? 1. ????????????? (
Sequential ) 2. ??????? ( Random ) 3.
?????????????????????? ( Indexed Sequential )
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????????????????????????????? ( Sequential File
) ?????????????????????????????
???????????????? ??????? (Records)
???????????????????????????????? ?????????????????
???????(field)???????????????????? ????????
?????????????????????????????????? ????
(Key)??? ??????? ????????????????????????????????
????????????? ????????????????????????????????????
????????????????? ????????????????????????????????
???
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??????????????????????????????????????????
??????? ??????????????????????????????????????????
??????????????? ??????? ??????????????????????????
??????????????? ?????? ???????????????????????????
????? ???????????????????????? ???????????????????
???????????????????????????? ????????? Update
???????????????? ?????????? ??????????????????????
?????????????????????????? ???????? ?????????????
1 ????????????????????? 1 ?????
????????????? ??????????????????
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Sequential File EMP_NO EMP_NAME
AGE WORK_AGE SALARY 1001
???????? ??????? 35 5 15000 1003 ?.?.????
?????? 25 2 8500 2001 ???????
??????? 30 3 12000 2005 ????????
??????? 26 2 8500 3001 ?????????
???????? 28 3 10000 3006 ?.?.?????
?????? 31 3 11000
??????????????
2005
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??????????????????????? ( Random File
) ??????????????????????? ???????????????????????
????? ????????????????????????????????????????????
?? (Direct) ?????????????????????????????????????
??? ????????????? ???????????????????????? Update
??????????????????????? Sequential
??????????????????????????????????????????????? ??
?????????????? ???? ???????????
??????????????????????? ??????????????????????????
??????????? field ??????? key ??????????
?????????????????????????????????????
????? ????????????????????????????????????????????
??
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??? Update ??????????????????????????????????? ??
????????? Sequential ??????????????? Update
???????? Update ???????????????????????
??????????????????????? Update ???????????????????
????????????? Sequential ????? ???????????? ??
?????????????????????????????????????? ???????????
?????????????????????????????????????? ???????????
???????????????????????????????? Update
????? ?????????????????????????????
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Random File EMP_NO EMP_NAME
WORK_AGE SALARY 1
1001 ???????? ??????? 5 15000 2 1003
?.?.???? ?????? 2 8500 3 2001 ???????
??????? 3 12000 4 2005 ????????
??????? 2 8500 5 3001 ?????????
???????? 3 10000 6 3006 ?.?.?????
?????? 3 11000
Record no.
??????????????
2005
4
Hashing Algorithm
37
?????????????????????????????????????? (Indexed
Sequential File ) ???????????????????????????????
??????????????????? ??????????????????????????????
??????????????????????????? ??????????
????????????????????????????????????????? ????????
?????????????? ???? ??????????? ????????????????
?????????? 2 ???? ??? 1. ??????????????????
(Index area) ?????????????????? ??????? 2.
?????????????? ???????? 2 ???? ??? 2.1 Prime
data area 2.2 Overflow area
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Index file
Data file
Record Location
Record Location
Key Field
Key
Data Record
0005 5811
0016 5812
0080 5901
0239 5902




0005 Diskette
0016 Ribbon
0080 Printer
0239 Scanner




5811 5812 5901 5902
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Database Technology

• DATABASE
• A collection of data organised to serve many
  applications efficiently by centralising the data
  and minimising redundant data.

40
THE DATABASE APPROACH TO DATA MANAGEMENT
The Contemporary Database Environment
41
THE DATABASE APPROACH TO DATA MANAGEMENT
Types of Databases

• Relational DBMS
• Hierarchical and Network DBMS
• Object-Oriented Databases

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THE DATABASE APPROACH TO DATA MANAGEMENT
Relational DBMS

• The most popular type of DBMS today for PCs as
  well as for larger companies and mainframes
• Represents all data in DB as two-dimensional
  tables called relations
• Similar to flat files but information in more
  than one file can easily be extracted and
  combined
• Relates data across tables based on common data
  element
• Examples DB2, Oracle, MS SQL Server

43
THE DATABASE APPROACH TO DATA MANAGEMENT
Relational Data Model
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EMPLOYEE-NO EMPLOYEE-NAME
SALARY DEPT-CODE DEPT-NAME
DEPT-BONUS 001 Mr. ANAN
BOONMA 55000 01
COMPUTER ENGINEER 3 002
Miss BOONSRI MAKMEE 10000
01 COMPUTER ENGINEER
3 003 Mr. TAWAT MEETHEP
7500 02 COMPUTER
SOFTWARE 3 004
Miss MALI WONGTHAI 8500
03 ACCOUNT 2 . .
.
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Key
EMPLOYEE
EMPLOYEE-NO EMPLOYEE-NAME SALARY DEPT-NO
SEQ-NO 01 001 Mr. ANAN
BOONMA 55000 01 002 Miss
BOONSRI MAKMEE 10000 02 001
Mr. TAWAT MEETHEP 7500 03
001 Miss MALI WONGTHAI 8500 .
. DEPT-CODE
DEPT-NAME DEPT-BONUS 01
COMPUTER ENGINEER 3 02
COMPUTER SOFTWARE 3
03 ACCOUNT 2 .
. .
Key
DEPARTMENT
46
SALESPERSON SALESPERSON SALES CUSTOMER
CUSTOMER WAREHOUSE WAREHOUSE
SALES NUMBER NAME
AREA NUMBER NAME
NUMBER LOCATION AMOUNT
3462 Waters
WEST 18765 DELTA Systems
4 Fargo
13540 3462 Waters
WEST 18830 A.Levy and
Sons 3 Bismarck
10600 3462 Waters
WEST 19242
Ranier Company 3
Bismarck 9700 3593
Dryne EAST 18841
R. W. Flood Inc. 2
Superior 11560
3593 Dryne
EAST 18899 Seward Systems
2 Superior
2590 3593 Dryne
EAST 19565 Stodolas
Inc. 1
Plymouth 8800 . .
. .
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SALESPERSON
SALES
SALESPERSON SALESPERSON SALES NUMBER
NAME AREA 3462
Waters WEST 3593
Dryne EAST
etc.
SALESPERSON CUSTOMER SALES NUMBER
NUMBER AMOUNT 3462
18765 13540 3462
18830 10600 3462
19242 9700 3593
18841 11560
3593 18899 2590
3593 19565
8800 etc.
WAREHOUSE
CUSTOMER
CUSTOMER CUSTOMER WAREHOUSE NUMBER
NAME NUMBER
18765 Delta Systems
4 18830 A. Levy and Sons
3 19242 Ranier Company
3 18841 R. W.
Flood Inc. 2 18899
Seward Systems 2 19565
Stodolas Inc. 1
etc.
WAREHOUSE WAREHOUSE NUMBER
LOCATION 4 Fargo
3 Bismarck 2
Superior 1
Plymouth etc.
The complete database