Dr. Mohamed Osman Hegazi 1 Database Systems Concepts Database Systems Concepts Course Outlines:...

Dr. Mohamed Osman Hegazi1

Database Systems ConceptsDatabase Systems Concepts

Course Outlines:

Introduction to Databases and DBMS.Database System Concepts and ArchitectureConceptual database designing (Data Modeling Using the ER Model)Logical database designing (1) mapping ER tor relation schemaLogical database designing (2) Functional Dependencies and Normalization for Relational DatabasesThe Relational Algebra SQL: Schema Definition, Constraints, Queries, and Views

Dr. Mohamed Osman Hegazi 2

maintenancemaintenance AhmedAhmed

AhmedAhmed

19981998

AliAli750750

205205

AhmedAhmed maintenancemaintenanceAliAli AhmedAhmed 19981998 205205750750

FnameFname SnameSname LnameLname DepartmentDepartment HDate HDate SalSal ExtPhExtPh

OmerOmer OsmanOsman TahaTaha AccountAccount 20012001 450450 301301

PersonalPersonal

DataBaseDataBase

DataData

1- introduction1- introduction

3

Definitions

Data: facts, text, graphics, images, sound, video segments (raw material)

Database: An organized collection of logically related data (data with meaning)

Information: Data processed to be useful in decision making

Metadata: Data that describes data

Dr. Mohamed Osman Hegazi

4

Useful information that managers can use for decision making and interpretation

Dr. Mohamed Osman Hegazi

Dr. Mohamed Osman Hegazi 5

Definitions: DBMS

Database Management System Software that defines a database, stores the data,

supports a query language, produces reports, and creates data entry screens.

Database management system (DBMS)

Dr. Mohamed Osman Hegaz 8

What is a Database System (DBMS Application)?What is a Database System (DBMS Application)?


Examples of Commercial Systems

Oracle Informix (Unix) DB2, SQL/DS (IBM) Access (Microsoft) SQL Server (Microsoft +) Many older (Focus, IMS, ...) mySQL ProgresSQL


Types of Data ModelsTypes of Data Models

Relational Data ModelMost commonly used model for traditional applications, and therefore basis for many commercially successful DBMS.

Legacy Data ModelsNetwork and Hierarchical Data Models.

Object Data ModelsNew paradigm, in response to applications with complex data and the success of object oriented concepts in software engineering.

Hierarchical Database Example

Network Database Example

Relational Database Concepts

Keys Referential integrity SQL Joining tables


Relation ComponentsRelation Components

Object Database Example


Schemas and InstancesSchemas and Instances

Most data models have the concept of “schema” and“instance”.Schema• A Schema is the metadata, or data describing data.• Schema is specified during database design, and is not

expected to change frequently.• Used to facilitate the understanding, use and management of

data.• Examples:

• In a library, metadata about a title would typically include a description of the content such as the author, the publication date, and the physical location.

• In the context of a camera, where the data is the photographic image. What could be the meta data?

16


Schemas and Instances (Cont…)Schemas and Instances (Cont…)

Instance• An Instance is the data in the database at a particular time.

• Instances are created during data updates and change frequently.

STUDENT

Name StudentNumber Class Major

COURSE

CourseName CourseNumber CreditHours Department

Database Schemas


Example Schema and InstanceExample Schema and Instance


Requirements specification

Database Design

Conceptual Database Design

Logical Database Design

Physical Database Design

Database implementation

Application Planning

Application Design

Application Implementation

Testing

Maintenance

ERUML

Mapping

Normalization

Design container , policy, Integrity

Create & Programming

Query processing and transaction

Database Administration


THE SYSTEMS DEVELOPMENT THE SYSTEMS DEVELOPMENT LIFE CYCLELIFE CYCLE

Planning

Analysis

Designing

Testing

Implementation


Conceptual Database Designing Provides concepts that are close to the way many users

perceive data. (modeling the collected information at a high-level of abstraction)

Logical Database Designing Provides concepts that arrange the data into a logical structure

which can then be mapped into the storage objects

Physical Database Designing Provide concepts that describe the details of how data is stored

in the computer.

Database Designing Database Designing

Centralized and Client/Server Architectures for DBMSs

Centralized DBMSs Architecture All DBMS functionality, application program execution,

and user interface processing carried out on one machine

Basic Client/Server Architectures

Client User machine that provides user interface

capabilities and local processing Server

System containing both hardware and software Provides services to the client machines

Such as file access, printing, archiving, or database access

Two-Tier Client/Server Architectures for DBMSs

Server handles Query and transaction functionality related to SQL

processing Client handles

User interface programs and application programs

Three-Tier and n-Tier Architectures for Web Applications

Application server or Web server Adds intermediate layer between client and the

database server Runs application programs and stores business

rules N-tier

Divide the layers between the user and the stored data further into finer components


Assignment 1

Choose a database application with which you are familiar. show a sample database for that application, using the notation below. - What types of additional information and constraints would you like to represent in the schema? - Think of several users for your database.

Assignment must be submitted on next week

Dr. Mohamed Osman Hegazi 1 Database Systems Concepts Database Systems Concepts Course Outlines:...

Documents

Transcript of Dr. Mohamed Osman Hegazi 1 Database Systems Concepts Database Systems Concepts Course Outlines:...