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

Dr. Mohamed Osman Hegazi 2 maintenanceAhmed Ahmed 1998 Ali AhmedmaintenanceAliAhmed FnameSnameLnameDepartmentHDateSal ExtPh OmerOsmanTaha Account Personal DataBase Data 1- 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

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 Hegaz8 What is a Database System (DBMS Application)?

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

Dr. Mohamed Osman Hegaz10 Types of Data Models Relational Data Model Most commonly used model for traditional applications, and therefore basis for many commercially successful DBMS. Legacy Data Models Network and Hierarchical Data Models. Object Data Models New paradigm, in response to applications with complex data and the success of object oriented concepts in software engineering.

Slide 11 Hierarchical Database Example

Slide 12 Network Database Example

Slide 13 Relational Database Concepts Keys Referential integrity SQL Joining tables

Dr. Mohamed Osman Hegaz14 Relation Components

Slide 15 Object Database Example

Dr. Mohamed Osman Hegaz16 Schemas 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? 16

Dr. Mohamed Osman Hegaz17 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 NameStudentNumberClassMajor COURSE CourseNameCourseNumberCreditHoursDepartment Database Schemas

Dr. Mohamed Osman Hegaz18 Example Schema and Instance

Dr. Mohamed Osman Hegaz19 ER UML Mapping Normalization Design container, policy, Integrity Create & Programming Query processing and transaction Database Administration

Dr. Mohamed Osman Hegaz20 THE SYSTEMS DEVELOPMENT LIFE CYCLE Planning Analysis Designing Testing Implementation

Dr. Mohamed Osman Hegaz21 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

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

Dr. Mohamed Osman Hegaz31 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