Database design
Download
1 / 24

Database Design - PowerPoint PPT Presentation


  • 157 Views
  • Updated On :

Database Design. Hacettepe University Department of Information Management DOK 322 : Database Management Systems. File Management Systems vs. DBMSs Advantages and Disadvatages of DBMS Components of DBMS MS Access 2000 (Lab). Last Time. Minimal Data Redundancy Consistency of Data

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Database Design' - varvara


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Database design l.jpg

Database Design

Hacettepe University

Department of Information Management

DOK 322: Database Management Systems


Last time l.jpg

File Management Systems vs. DBMSs

Advantages and Disadvatages of DBMS

Components of DBMS

MS Access 2000 (Lab)

Last Time


Dbms benefits l.jpg

Minimal Data Redundancy

Consistency of Data

Integration of Data

Sharing of Data

Ease of Application Development

Uniform Security, Privacy, and Integrity Controls

Data Accessibility and Responsiveness

Data Independence

Reduced Program Maintenance

DBMS Benefits


Database environment l.jpg

CASE

Tools

User

Interface

Application

Programs

Repository

DBMS

Database

Database Environment


Database components l.jpg
Database Components

DBMS

===============

Design tools

Table Creation

Form Creation

Query Creation

Report Creation

Procedural

language

compiler (4GL)

=============

Run time

Form processor

Query processor

Report Writer

Language Run time

Database

Application

Programs

Database contains:

User’s Data

Metadata

Indexes

Application Metadata

User

Interface

Applications

Kroenke, Database

Processing


Terms and concepts l.jpg

Database:

A self-describing collection of integrated records (Kroenke).

A collection of similar records with relationships between the records. (Rowley)

A collection of stored operational data used by the application systems of some particular enterprise. (C.J. Date)

Terms and Concepts


Terms and concepts7 l.jpg

Enterprise

Organization

Entity

Person, Place, Thing, Event, Concept...

Attributes

Data elements (facts) about some entity

Also sometimes called fields or items or domains

Data values

instances of a particular attribute for a particular entity

Terms and Concepts


Terms and concepts8 l.jpg

Key

an attribute or set of attributes used to identify or locate records in a file

Primary Key

an attribute or set of attributes that uniquely identifies each record in a file

Terms and Concepts


Terms and concepts9 l.jpg

Models

(1) Levels or views of the Database

Conceptual, logical, physical

(2) DBMS types

Relational, Hierarchic, Network, Object-Oriented, Object-Relational

Terms and Concepts


Models 1 l.jpg

Application 1

Application 2

Application 3

Application 4

External

Model

External

Model

External

Model

External

Model

Application 1

Conceptual

requirements

Application 2

Conceptual

requirements

Conceptual

Model

Logical

Model

Internal Model

Application 3

Conceptual

requirements

Application 4

Conceptual

requirements

Models (1)


Database system life cycle l.jpg
Database System Life Cycle

Physical

Creation

2

Conversion

3

Design

1

Growth,

Change, &

Maintenance

6

Integration

4

Operations

5


Another view of the life cycle l.jpg
Another View of the Life Cycle

Integration

4

Operations

5

Design

1

Physical

Creation

2

Conversion

3

Growth,

Change

6


Database models l.jpg

Models(2): DBMS types

Hierarchical

Network

Relational

Object-Oriented

Database Models


Database data models l.jpg

Hierarchical Model

Similar to data structures in programming languages.

Books

(id, title)

Authors

(first, last)

Publisher

Subjects

Database Data Models


Database data models15 l.jpg

Network Model

Provides for single entries of data and navigational “links” through chains of data.

Authors

Subjects

Books

Publishers

Database Data Models


Database data models16 l.jpg

Relational Model

Provides a conceptually simple model for data as relations (typically considered “tables”) with all data visible.

Database Data Models


Database data models17 l.jpg

Object Oriented Data Model

Encapsulates data and operations as “Objects”

Books

(id, title)

Authors

(first, last)

Publisher

Subjects

Database Data Models


Database design process l.jpg
Database Design Process

Application 1

Application 2

Application 3

Application 4

External

Model

External

Model

External

Model

External

Model

Application 1

Conceptual

requirements

Application 2

Conceptual

requirements

Conceptual

Model

Logical

Model

Internal Model

Application 3

Conceptual

requirements

Application 4

Conceptual

requirements


Database design process19 l.jpg

Conceptual Requirements

Systems Analysis Process

Examine all of the information sources used in existing applications

Identify the characteristics of each data element

numeric

text

date/time

etc.

Examine the tasks carried out using the information

Examine results or reports created using the information

Database Design Process


Database design process20 l.jpg

Conceptual Model

Merge the collective needs of all applications

Determine what Entities are being used

Some object about which information is to maintained

What are the Attributes of those entities?

Properties or characteristics of the entity

What attributes uniquely identify the entity

What are the Relationshipsbetween entities

How the entities interact with each other?

Database Design Process


Database design process21 l.jpg

Logical Model

How is each entity and relationship represented in the Data Model of the DBMS

Hierarchic?

Network?

Relational?

Object-Oriented?

Database Design Process


Database design process22 l.jpg

Internal Model

Choices of index file structure

Choices of data storage formats

Choices of disk layout

Database Design Process


Database design process23 l.jpg

External Model

User views of the integrated database

Making the old (or updated) applications work with the new database design

Database Design Process


Developing a conceptual model l.jpg

Overall view of the database that integrates all the needed information discovered during the requirements analysis.

Elements of the Conceptual Model are represented by diagrams, Entity-Relationship or ER Diagrams, that show the meanings and relationships of those elements independent of any particular database systems or implementation details.

Developing a Conceptual Model