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RESEA RC H G RO U P
InformationManagement
Chapter 1
Database & Database Users
Computer Science Centre
University of Indonesia
RESEA RC H G RO U P
InformationManagement
Applications of databases
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Banks
Hospital
Library
Supermarket
Magazine & newspaper subscriptions
RESEA RC H G RO U P
InformationManagement
Extensions
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Multimedia databases
Geographic Information Systems
Data warehouse
On-line analytical processing (OLAP)
Active & real-time databases
RESEA RC H G RO U P
InformationManagement
Definition
• Collection of related data which has
meaning
• Examples: MS-Access, Oracle, Sybase,
Informix, dBase, FoxPro
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InformationManagement
Properties
• Represents some aspect of the real
world, called miniworld or Universe of
Discourse
• Logically coherent collection of data
with some inherent meaning
• Designed, built and populated for
specific purpose
RESEA RC H G RO U P
InformationManagement
More example
• Small database: phonebook on your
handphones!
• Large & complex database: tax office
database
• Why is it much more complex?
RESEA RC H G RO U P
InformationManagement
DBMS
Database Management System is a
collection of softwares that facilitates
the process of
– defining,
– constructing and
– manipulating
database for various applications
RESEA RC H G RO U P
InformationManagement
Database System Environment
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InformationManagement
‘University’ database example
• Has 5 files (‘tables’):
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Student
Course
Section
Grade Report
Prerequisite
• See how do they relate to each other!
• How do we define, construct & manipulate?
RESEA RC H G RO U P
InformationManagement
RESEA RC H G RO U P
InformationManagement
Characteristic of Database
Approach
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Self describing nature
Insulation between program and data
Support of multiple views of data
Sharing of data & multiuser transaction
processing
RESEA RC H G RO U P
InformationManagement
Self describing nature
• As oppose to unstructured data
• Meta-data describes the structure of the
database
• In traditional file processing, data
definition is part of the application
program
RESEA RC H G RO U P
InformationManagement
Insulation between programs &
data
• Changes to the data structure does not
generally require changing the program
• For example, adding a new field ‘Birthday’
• The ‘data structure’ is not in the program
• We call this program-data independence
• DBMS provides conceptual representation
• User or programmer does not need to know
how the DBMS store the data in the disk / file.
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InformationManagement
Multiple Views
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Sharing & Multiuser
• DBMS provides concurrency control to
ensure ‘correct’ behavior when multiple
users update the same database
• Example: airline seat reservation
• It is called On-Line Transaction
Processing (OLTP)
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InformationManagement
The Actors
• Database administrator
– Authorizing access rights
• Database designers
– Defines the structure of data to be stored
• End users:
– Sophisticated non-programmer users
– Naïve users
• Application programmers
RESEA RC H G RO U P
InformationManagement
Advantages of Using a DBMS
• Controlling redundancy
• Restricting unauthorized access
• Provides persistent storage for data
structures
• Permits inferencing
• Multiple user interfaces
• Represents complex relations amongst data
• Enforcing integrity constraints
• Provides backup & recovery
RESEA RC H G RO U P
InformationManagement
Implications of Database to
Organizations
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Could enforce standards
Reduce application development time
Flexibility
Availability of up-to-date information
Economies of scale