Introduction to Database Systems Ch. 1, Ch. 2Teaching StaffCommunicationTextbooksThe Study of DatabasesCourse OutlinePrerequisiteRequirementsGradingThe Course ProjectWhat is a Database System?Why Use a DBMS?What Does a DBMS Offer?How to Use a DBMSData Model & DB SchemaEntity-Relationship ModelRelational ModelAbstract levels of DB SchemaExample: University DatabaseData IndependenceDatabase LanguageWho Are Happy w/ Databases?Structure of a DBMSSummaryLook AheadIntroduction to Database SystemsCh. 1, Ch. 2Mr. John OrtizDept. of Computer ScienceUniversity of Texas at San AntonioLecture 1 Introduction 2Teaching StafInstructor: Mr. John OrtizOffice: TBDPhone: NULLEmail: [email protected] hour: 6 – 7pm, T & R, after any classTA: NULLLecture 1 Introduction 3CommunicationWeb page of Dr. Zhang: -use as a GUIDE ONLY http://www.cs.utsa.edu/~wzhang/cs3743/homeContains everything about the course: syllabus, announcement, assignments, project, lecture notes, etc.Generally, I will use Dr. Zhang’s outline, but do not expect my tests to look like any of hisMailing list: [email protected] 1 Introduction 4TextbooksRequired textbook:Fundamentals of Database Systems, 3rd Edition, by R. Elmasri & S. NavatheRecommended textbook:Oracle8 Programming, A Primer, by R. SunderramanOther books: Reserved in JPL under instructor’s nameLecture 1 Introduction 6The Study of DatabasesSeveral aspects:Modeling and design of databasesDatabase programming: querying and update operationsDatabase implementationDatabase study cuts across many fields of Computer Science: OS, languages, AI, Logic, multimedia, theory, ...?Lecture 1 Introduction 7Course OutlineFrom a user perspectiveBasic concepts: database, DBMS, …Data modeling: ER, relational, OO, …Database design: logical & physical designUse of databases: query, update, loading, …Database applications: design, implementingFrom a system perspectiveData storage: device, structure, access, …Query processing, optimizationTransaction processing, and more …Lecture 1 Introduction 10PrerequisiteProgramming (either C/C++ or Java)Unix operating systemData structure & algorithmMathematics (logic, sets, algebra, …)Lecture 1 Introduction 11RequirementsRead, read, readTextbooks, System manual, …Practice, practice, practiceHomework, projectPlay with sample programs, examples in books, your own ideas, …Communicate, communicate, communicateWith instructor, TA, each other, …Be honestNo cheating, plagiarism, …Lecture 1 Introduction 12GradingAssignments 150 ptsProject 200 ptsMidterm I 150 ptsMidterm II 150 ptsFinal Exam 300 ptsIntangibles 50 ptsLecture 1 Introduction 13The Course ProjectGoalDevelop a realistic database applicationGain experience in team workTopic? Your choice with my approval, be creativeTeam4 members, elect a leader, complete self-organizing, collaboration, overcome diferencesMilestonesProgress in 5 partsLecture 1 Introduction 14What is a Database System?Database System = Database + DBMSA Database isA large, integrated collection of dataModels a real-world enterprise.Entities (e.g., students, courses)Relationships (e.g., Mary takes CS123)A Database Management System (DBMS) is a software package designed to store and manage databases easily and efficiently.Lecture 1 Introduction 15Why Use a DBMS?Suppose we need to build a university information system. How do we store the data? (use file structures…)query the data? (write programs…)Update data safely? (more programs…)provide diferent views on the same data? (registrar versus students) (more prog…)deal with crashes? (more prog…)Way too complicated! Go buy a DBMS!Lecture 1 Introduction 16What Does a DBMS Ofer?Efficient data storage.Abstract data model.Query & data manipulation language.Diferent views of the data.Data integrity & security.Support application development.Concurrent access by multiple users.Crash recovery.Data analysis, mining, visualization, …Lecture 1 Introduction 17How to Use a DBMSRequirements modeling (conceptual)Decide what entities should be part of the application and how they are relatedSchema design and database creationDecide on a database schemaDefine the schema to the DBMSLoad data into the databaseAccess to dataUse a database languageWrite database application programsUse database application programsLecture 1 Introduction 18Data Model & DB SchemaA data model is a collection of concepts for describing data in a DB, includingObjectsRelationships among objectsConstraints on objects & relationships Operations on objects & relationshipsA schema is a description of a particular collection of data, using a given data model.An instance is a particular set of data in the DB.Lecture 1 Introduction 19Entity-Relationship ModelA popular conceptual model.Concepts include entities, relationships, constraints. (see p.63 in text)Courses EnrolledSID NameCIDCreditsmnStudentsAgeGPACnameGradeLecture 1 Introduction 20Relational ModelThe most widely used logical model today.Concepts include: tables, constraints, operations, … Students(sid: string, name: string, login: string, age: integer, gpa:real) Courses(cid: string, cname:string, credits:integer) Enrolled(sid:string, cid:string, grade:string)Lecture 1 Introduction 21Abstract levels of DB SchemaViews describe how users see the data. Conceptual schema defines logical structure using a data modelPhysical schema describes the files and indices used.Physical SchemaConceptual SchemaView 1 View 2 View 3Lecture 1 Introduction 22Example: University DatabaseA View for registrar officeCourse_info(cid:string,enrollment:integer)The conceptual schema: Students(sid: string, name: string, login:string, age: integer, gpa:real) Courses(cid: string, cname:string, credits:integer) Enrolled(sid:string, cid:string, grade:string)the physical schema:Relations stored as unordered files. Index on first column of Students.Lecture 1 Introduction 23Data IndependenceDBMS is able to hide details of lower level schema from clients of higher level schemaLogical data independence: Protects views from changes in logical (conceptual) structure of data.Physical data independence: Protects conceptual schema from