Transcript Chapter 1 of Database Design, Application Development and

Introduction to Database
Management
Outline
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Database characteristics
DBMS features
Architectures
Organizational roles
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Initial Vocabulary
 Data: raw facts about things and events
 Information: transformed data that has
value for decision making
 Essential to organize data for retrieval and
maintenance
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Database Characteristics
 Persistent : stable storage
 Shared : multiple users and uses
 Interrelated : data stored as entities and
relationships
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University Database
Registration
Grade
Recording
Entities:
students, faculty, courses,
offerings, enrollments
Relationships:
faculty teach offerings,
students enroll in
offerings, offerings made
of courses, ...
Faculty
Assignment
Course
Scheduling
University Database
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Water Utility Database
Billing
Meter
Reading
Entities:
customers, meters, bills,
payments, meter readings
Relationships:
bills sent to customers,
customers make payments,
customers use meters, ...
Payment
Processing
Service Start/
Stop
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Database Management
System (DBMS)
 Collection of components that support
data acquisition, dissemination, storage,
maintenance, retrieval, and formatting
 Enterprise DBMSs
 Desktop DBMSs
 Embedded DBMSs
 Major part of information technology
infrastructure
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Database Definition
 Define database structure before using a
database
 Tables and relationships
 SQL CREATE TABLE statement
 Graphical tools
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University Database
Relationships
Tables
s
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University Database (ERD)
Student
Offering
Faculty
StdSSN
StdClass
StdMajor
StdGPA
OfferNo
OffLocation
OffTime
FacSSN
FacSalary
FacRank
FacHireDate
Teaches
Has
Supervises
Accepts
Course
Registers
Enrollment
EnrGrade
CourseNo
CrsDesc
CrsUnits
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Nonprocedural Access
 Query: request for data to answer a
question
 Indicate what parts of database to retrieve
not the procedural details
 Improve productivity and improve
accessibility
 SQL SELECT statement and graphical
tools
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Graphical Tool for
Nonprocedural Access
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Application Development
 Form: formatted document for data entry
and display
 Report: formatted document for display
 Use nonprocedural access to specify data
requirements of forms and reports
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Sample Data Entry Form
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Sample Report
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Procedural Language Interface
 Combine procedural language with
nonprocedural access
 Why
 Batch processing
 Customization and automation
 Performance improvement
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Transaction Processing
 Transaction: unit of work that should be
reliably processed
 Control simultaneous users
 Recover from failures
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Database Technology Evolution
Era
1960s
Generation
1st Generation
Orientation
File
1970s
2nd Generation
Network
Navigation
1980s
3rd Generation
Relational
1990s
4th Generation
Object
Major Features
File structures and
proprietary program
interfaces
Networks and hierarchies
of related records,
standard program
interfaces
Non-procedural
languages, optimization,
transaction processing
Multi-media, active,
distributed processing,
XML enabled
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DBMS Marketplace
 Enterprise DBMS
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Oracle: dominates in Unix; strong in Windows
SQL Server: strong in Windows
DB2: strong in mainframe environment
Significant open source DBMSs: MySQL,
Firebird, PostgreSQL
 Desktop DBMS
 Access: dominates
 FoxPro, Paradox, Approach, FileMaker Pro
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Data Independence
 Software maintenance is a large part
(50%) of information system budgets
 Reduce impact of changes by separating
database description from applications
 Change database definition with minimal
effect on applications that use the
database
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Three Schema Architecture
View 1
External to
Conceptual
Mappings
Conceptual
to Internal
Mappings
View 2
Conceptual
Schema
Internal
Schema
View n
External
Level
Conceptual
Level
Internal
Level
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Differences among Levels
 External
 Forms
 Reports
 Conceptual
 Tables
 Internal
 Files needed to store the tables
 Extra files to improve performance
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Client-Server Architecture
a) Client, server, and
database on the
same computer
b) Mulitple clients and 1 server
on different computers
Client
Client
Server
Server
Client
Client
Database
Database
c) Multiple servers and databases on different computers
Client
Server
Server
Client
Client
Client
Database
Database
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Organizational Roles
Specialization
Functional User
Indirect
Parametric
Information Systems
Power
DBA
Technical
Analyst/Programmer
Management
Non Technical
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Database Specialists
 Database administrator (DBA)
 More technical
 DBMS specific skills
 Data administrator
 Less technical
 Planning role
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Summary
 Databases and database technology vital
to modern organizations
 Database technology supports daily
operations and decision making
 Nonprocedural access is a crucial feature
 Many opportunities to work with databases
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