First 4 WeeksTextbooks for COSC 6340Lectures in COSC 3480DatabasesSlide 5A Brief History NoteAn Example File SystemProblems of File Systems (1)Problems of File Systems (2)Problems of File Systems (3)Problems of File Systems (4)Problems of File Systems (5)Database History (Continued)An IMS QueryHistory of Database (Continued)History of Database (Continued)Slide 17Database LanguagesPersons Involving DBS (1)Persons Involving DBS (2)Persons Involving DBS (3)After This Course, You Will BePopular Topics in DatabasesReview: Why are integrated databases popular?Slide 25Data ModelSchema for the Library Example using the E/R Data ModelRelational Schema for Library Example in SQL/92Example InstancesReferential Integrity in SQL/92Example of an Internal Schema for the Library ExampleExample: Stored Database3 Schema ArchitectureData IndependenceSlide 35Disks and FilesWhy Not Store Everything in Main Memory?Components of a DiskAccessing a Disk PageSupport for TransactionsReview: The ACID propertiesExampleAtomicity of TransactionsConcurrency in a DBMSExample (Contd.)SummaryChristoph F. EickIntroduction File and Database SystemsFirst 4 Weeks1. Introduction to Databases2. Course Information 3. Grading and Other Things4. Questionnaire5. The Relational Data Model6. Relational Algebra / SQL Part17. The E/R Data Model 8. SQL Part2Week1/2Weeks 2-4Christoph F. EickIntroduction File and Database SystemsTextbooks for COSC 6340Required Text: Raghu Ramakrishnan and Johannes Gehrke, Data Management Systems, McGraw Hill, Third Edition, 2002 Other books with relevant material: Ramez Elmasri and Shamkant Navathe, Fundamentals of Database Systems, Fourth EditionChristoph F. EickIntroduction File and Database SystemsLectures in COSC 34801. Basic Concepts of Database Management (2-3 classes; Chapter 1, 2.1,2.2, 2.3; instructor teaching material) 2. Introduction to the Relational Data Model (1.5 classes; Chapter 3.1, 3.2, 3.3, 3.4, 3.6)3. Introduction to the Relational Algebra and SQL (3-4 classes; Chapter 4.2, Chapter 5)4. Conceptual Schema Design using the Entity Relationship Data Model (2-3 classes; instructor material; Chapters 2.4, 2.5) 5. Relational Database Design and Normalization (2-3 classes; instructor material, Chapter 19) 6. Introduction to KDD and Data Warehousing (2 classes; instructor material, Chapters 25 and 26) 7. Disks, Files, Storage Structures, Index Structures and Physical Database Design (4 classes, Chapter 8, 9, 10, 11.1, 11.2, 13, 20) 8. Internet Databases and XML (1-2 classes; Chapter 7 and 27) 9. Query Optimization (1 class; Chapter 12, only if enough time left)10. Summary: Where Do We Stand? (1 class; instructor material)Christoph F. EickIntroduction File and Database SystemsDatabasesDefinition: A database is a collection of data with the following properties:It represents certain aspect of the real-world.Its data are logically related.It is created for a specific purpose.Christoph F. EickIntroduction File and Database SystemsDefinition: A database management system (DBMS) is a set of software that are used to define, store, manipulate and control the data in a database.define --- define data types, structures and constraints.store --- store data; provide efficient access.manipulate --- perform retrieval and update operations using a query language.control --- control access to data. Database System = Database + DBMSDBMSChristoph F. EickIntroduction File and Database SystemsA Brief History Note Database technology has a history of about 40 years.Database technology has gone through several generations .First Generation: File systems, 50's -- 60's A typical file system consists of a set of independent files, and a number of application programs Definition: A file stores a set of record (on a disk drive) all of which have the same format.Christoph F. EickIntroduction File and Database SystemsAn Example File System A banking system may have files for customers, saving accounts and checking accounts; application programs to deposit and withdraw money, to find balance, etc.different files are used for customers, saving and checking accountsChristoph F. EickIntroduction File and Database SystemsProblems of File Systems (1) It is difficult to support new applications. Two existing application programs: (i) find customers who have a checking account (ii) find customers who have a saving account Need a new program to find the customers who have a checking account and a saving account.Christoph F. EickIntroduction File and Database SystemsProblems of File Systems (2)It has no centralized control of all data.  Files are often created for a particular application. Files are created and managed independently.Christoph F. EickIntroduction File and Database SystemsProblems of File Systems (3)There often exists severe data redundancy and inconsistency. Checking-Account: Acct#, Owner-name, Owner-SSN, Owner-Addr, Balance, ... Saving-Account: Acct#, Owner-name, Owner-SSN, Owner-Addr, Balance, Interest, …Christoph F. EickIntroduction File and Database SystemsProblems of File Systems (4)It lacks concurrency control. Concurrency control: prevent mutual interference of concurrent requests.Example (Airplane ticket reservation): Consider the situation when two customers are trying to book the only ticket left for a flight through two operators at about the same time.Christoph F. EickIntroduction File and Database SystemsProblems of File Systems (5)Weak security Can not provide multiple views of the same dataLack isolation between program and dataLack self-describing featureChristoph F. EickIntroduction File and Database SystemsDatabase History (Continued)Second Generation: Hierarchical database systems (HDBS), late 60's -- early 70'sBest known HDBS: IMS (Information Management System of IBM).One-to-many relationships between parent records and child records which can have different types.Data are organized in treesRecords are connected by pointers.Christoph F. EickIntroduction File and Database SystemsAn IMS QueryQuery: find all Binghamton University students whose major is computer science and whose GPA is higher than 3.5. GU University (Name = `Binghamton University') Department (Name = `Computer Science') Student (GPA > 3.5) L1: GNP Student (GPA > 3.5) Goto L1Christoph F. EickIntroduction File and Database SystemsHistory of Database (Continued)Third Generation: Network