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Chapter 1
An Overview of Database
Management
Prof. Yin-Fu Huang
CSIE, NYUST
1.1 Introduction
 A database system ⇒ a computerized record-keeping system
 Operations:
1) adding new, empty files to the database
2) inserting data into existing files
3) retrieving data from existing files
4) deleting data from existing files
5) changing data in existing files
6) removing existing files from the database
(See Fig. 1.1, 1.2, & 1.3)
Advanced Database System
Yin-Fu Huang
Advanced Database System
Yin-Fu Huang
Advanced Database System
Yin-Fu Huang
1.2 What is a Database System ?
 A database system
Advanced Database System
Yin-Fu Huang
1.2 What is a Database System ? (cont.)
 Four components:
1) data ⇒ integrated & shared (See Fig. 1.5)
2) hardware ⇒ the second storage volumes,
the processors, & main memory
3) software ⇒ database management system (DBMS)
4) users ⇒ application programmers, end users, & database administrator
(DBA)
Advanced Database System
Yin-Fu Huang
1.3 What is a Database ?
 A database ⇒ persistent data
 Entities & Relationships
Example: E/R diagram (See Fig. 1.6)
A number of points:
1) ternary relationship
2) one relationship involving just one entity type
3) more relationships between entities
 Properties
 Data and data models
Advanced Database System
Yin-Fu Huang
Advanced Database System
Yin-Fu Huang
1.4 Why Database ?


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Centralized control of data
Data administration (manager)
Database administration (technician)
Benefits of the database approach
 The data can be shared
 Redundancy can be reduced
 Inconsistency can be avoided
 Transaction support can be provided
 Integrity can be maintained
 Security can be enforced
 Conflicting requirements can be balanced
 Standards can be enforced
Advanced Database System
Yin-Fu Huang
1.5 Data Independence
 The immunity of
applications to change in
physical representation and
access technique
 Stored field, stored record,
stored file (See Fig. 1.7)
Advanced Database System
Yin-Fu Huang
1.6 Relational Systems and Others
 The oldest systems:
 Inverted list
 Hierarchic
 Network
 Relation systems: DB2, Ingres II, Informix Dynamic Server,
Microsoft SQL server, Oracle 9i, Sybase Adaptive Server
(See Fig. 1.8)
 Object systems: GemStone, Versant ODBMS
Advanced Database System
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Advanced Database System
Yin-Fu Huang
The End.
Advanced Database System
Yin-Fu Huang