Dr. Mohamed Osman Hegazi 1 Database Systems Concepts Database Systems Concepts Course Outlines: Introduction to Databases and DBMS. Database System Concepts and Architecture Conceptual database designing (Data Modeling Using the ER Model) Logical database designing (1) mapping ER tor relation schema Logical database designing (2) Functional Dependencies and Normalization for Relational Databases The Relational Algebra SQL: Schema Definition, Constraints, Queries, and Views
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Dr. Mohamed Osman Hegazi 1 Database Systems Concepts Database Systems Concepts Course Outlines: Introduction to Databases and DBMS. Database System Concepts.
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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
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
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Useful information that managers can use for decision making and interpretation
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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)
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What is a Database System (DBMS Application)?What is a Database System (DBMS Application)?
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Examples of Commercial Systems
Oracle Informix (Unix) DB2, SQL/DS (IBM) Access (Microsoft) SQL Server (Microsoft +) Many older (Focus, IMS, ...) mySQL ProgresSQL
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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.
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Hierarchical Database Example
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Network Database Example
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Relational Database Concepts
Keys Referential integrity SQL Joining tables
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Relation ComponentsRelation Components
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Object Database Example
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Schemas and InstancesSchemas and Instances
Most data models have the concept of “schema” and“instance”.Schema• A Schema is the meta- data, 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?
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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
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Example Schema and InstanceExample Schema and Instance
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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
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THE SYSTEMS DEVELOPMENT THE SYSTEMS DEVELOPMENT LIFE CYCLELIFE CYCLE
Planning
Analysis
Designing
Testing
Implementation
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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
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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.