Transcript Competencies (Page 1 of 2)

12
DATABASES
McGraw-Hill Technology Education
© 2006 by the McGraw-Hill Companies, Inc. All rights reserved.
Competencies (Page 1 of 2)
Distinguish between the
physical and logical
view of data
Describe how data is
organized: characters,
fields, records, files,
and databases
Describe databases,
database issues, and
database management
systems (DBMS)
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Competencies (Page 2 of 2)
Describe the five data
models: hierarchical,
network, relational,
multidimensional, and
object-oriented
Distinguish among
individual, company,
distributed,
proprietary, and Web
databases
Recognize strategic
database uses and
security concerns
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Data
Facts or observations
about people, places,
things, and events
Two ways to view
data
Physical view
Logical view
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Data Organization
Field
Record
File
Database
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Key Field
Unique identifier also
known as primary field or
primary key
Common examples
Social security number
Driver’s license
Credit card account
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Batch Versus
Real-time Processing (Page 1 of 2)
Batch processing – data is collected over hours, days,
etc. Processed all at once as a “batch”
Batch Processing
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Batch Versus
Real-Time Processing (Page 2 of 2)
Real-time processing -- now
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Need for Database Management Systems
Efficient data access, processing.
Less data redundancy
Data integrity
Sharing – one department to another
Security – passwords to access
Access data entry form
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Subsystems of a Database
Management System
DBMS engine
MS Access, MS SQL Server, Oracle
Bridge between the logical view and
physical view
Data definition subsystem
Data dictionary: defines types of data
in each field
Data manipulation subsystem
Provides tools for analyzing and
maintaining data
Query-by-example
Structured query language (SQL)
Application generation subsystem
Create data entry forms
interface with common programming
languages e.g. visual basic
Data administration subsystem
Manage the database system: security,
backup, recovery, performance
monitoring
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DBMS Structure
Data models define
rules and standards for
data in a database – the
five data models are:
Hierarchical database
Network database
Relational database
Multidimensional
database
Object-oriented database
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Hierarchical Database
Fields or records are
structured in nodes
Nodes are point
connected like branches
One parent per node
Parent has several child
nodes (one-to-many
relationship)
Airline reservation system
Return
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Network Database
Hierarchical node
arrangement
Each child node may
have more than one
parent node (Many-tomany relationship)
Additional nodes are
called pointers
University Student System
Return
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Relational Database
Most flexible
Data stored in table
called a relation
Tables consist of rows
and columns
Tables related via a
common data item
Easy to use
Return
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Multidimensional Database
A variation and an extension of the relational
model
Includes a hyper cube
Good for representing complex relationships
Advantages over relational
Conceptualization
Processing speed
Return
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Object-Oriented Database
Works with
unstructured data
Photographs
Graphics
Audio
Video
Objects contain
both data
and instructions
Organize using objects,
classes, entities,
attributes, and methods
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Types of Databases
The five classifications of databases include:
Individual or microcomputer database
Company or shared
Operational
User
Distributed
Web database
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Database Uses and Issues
Strategic uses
Special type of database called data warehouse
Data mining used to search database
Security
Databases are valuable
Protection necessary
Electronic fingerprint pads
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A Look to the Future
Xperanto
Enhancement to searching
for data
Access to structured
(relational databases) and
unstructured data (word
processing and spreadsheet
files)
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Discussion Questions (Page 1 of 2)
Describe the five logical data groups or
categories.
What is the difference between batch
processing and real-time processing?
Identify and define the five part of DBMS
programs.
What are the five types of databases? Why does
more than one kind of database exist?
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Discussion Questions (Page 2 of 2)
What are some of the benefits and limitations
of databases? Why is security a concern?
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Example— Simple Banking Business
Bank has many customers who open and
maintain one or more accounts.
For each customer
Name, address, unique ID, account(s)
example
For each account
Account number, CustomerID, account type, balance
example
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