Database Systems Concepts Course Outlines l l l
Database Systems Concepts Course Outlines: l l l l 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 1 Dr. Mohamed Osman Hegazi
1 - introduction Data maintenance Ahmed 750 205 1998 Ali Data. Base Personal Fname Sname Lname Department Ahmed Omer Ali HDate Sal Ext. Ph Ahmed maintenance 1998 750 205 Account 450 301 Osman Taha 2001 Dr. Mohamed Osman Hegazi 2
Definitions l l 3 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
Useful information that managers can use for decision making and interpretation 4 Dr. Mohamed Osman Hegazi
Definitions: DBMS l Database Management System l Software that defines a database, stores the data, supports a query language, produces reports, and creates data entry screens. Dr. Mohamed Osman Hegazi 5
Database management system (DBMS)
What is a Database System (DBMS Application)? Dr. Mohamed Osman Hegaz 8
Examples of Commercial Systems l l l l Oracle Informix (Unix) DB 2, SQL/DS (IBM) Access (Microsoft) SQL Server (Microsoft +) Many older (Focus, IMS, . . . ) my. SQL Progres. SQL Dr. Mohamed Osman Hegaz 9
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. Dr. Mohamed Osman Hegaz 10
Hierarchical Database Example Slide 11
Network Database Example Slide 12
Relational Database Concepts l l Keys Referential integrity SQL Joining tables Slide 13
Relation Components Dr. Mohamed Osman Hegaz 14
Object Database Example Slide 15
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? Dr. Mohamed Osman Hegaz 16
Schemas and Instances (Cont…) STUDENT Name Student. Number Class Major Database Schemas COURSE Course. Name Course. Number Credit. Hours Department Instance • An Instance is the data in the database at a particular time. • Instances are created during data updates and change frequently. Dr. Mohamed Osman Hegaz 17
Example Schema and Instance Dr. Mohamed Osman Hegaz 18
UML ER Mapping Normalization Design container , policy, Integrity Create & Programming Query processing and transaction Database Administration Dr. Mohamed Osman Hegaz 19
THE SYSTEMS DEVELOPMENT LIFE CYCLE Planning Testing Analysis Implementation Designing Dr. Mohamed Osman Hegaz 20
Database Designing l Conceptual Database Designing l Provides concepts that are close to the way many users perceive data. (modeling the collected information at a high-level of abstraction) l Logical Database Designing l l Provides concepts that arrange the data into a logical structure which can then be mapped into the storage objects Physical Database Designing l Provide concepts that describe the details of how data is stored in the computer. Dr. Mohamed Osman Hegaz 21
Centralized and Client/Server Architectures for DBMSs l Centralized DBMSs Architecture l All DBMS functionality, application program execution, and user interface processing carried out on one machine
Basic Client/Server Architectures l Client l l User machine that provides user interface capabilities and local processing Server l l System containing both hardware and software Provides services to the client machines l Such as file access, printing, archiving, or database access
Two-Tier Client/Server Architectures for DBMSs l Server handles l l Query and transaction functionality related to SQL processing Client handles l User interface programs and application programs
Three-Tier and n-Tier Architectures for Web Applications l Application server or Web server l l l Adds intermediate layer between client and the database server Runs application programs and stores business rules N-tier l 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 Hegaz 31
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