Introduction to DatabaseSlide 2Database SystemIntroductionExamples of DatabasesSlide 6Slide 7Slide 8Slide 9Slide 10Slide 11File based system v.s. DBMSTraditional File-Based SystemsDatabase ApproachFile-Based SystemThe Database Management System (DBMS)Slide 17Components of the DBMS EnvironmentRoles in the Database EnvironmentRoles in the Database Environment (2)Roles in the Database Environment (3)Slide 22Slide 23Slide 24Advantages of DBMSAdvantages of DBMS (1/2)Advantages of DBMS (2/2)Slide 28Database DisadvantageDisadvantages of DBMSSlide 31History of DBMSSlide 33Introduction to DatabaseAIT632Chapter 1Sungchul HongDatabase System•The most important development in the field of software engineering.•Database serve as the foundation for considerable progress in the basic science fields ranging from computing to biology.Introduction•Database–A collection of related data.•DBMS (Database Management System)–The software that manages and controls access to the database.•Database application–A program that interacts with the database at some point in its execution.Examples of Databases•Supermarket–Inventory–Customer service•Credit card•Booking a ticket at the travel agents•Using the local library•University•??Geographical Information SystemStaffstaffNo fName lName position sex DOB salary branchNoSL21 John White Manager M Oct/1/45 30000 B005SG37 Ann Beech Assistant F Nov/10/60 12000 B003SG14 David Ford Supervisor M Mar/24/58 18000 B003SA9 Mary Howe Assistant F 19/Feb/70 9000 B007SG5 Susan Brand Manager F Jun/3/40 24000 B003SL41 Julie Lee Assistant F Jun/13/65 9000 B005SELECT staffNo, fName, lName, position, salaryFROM StaffWHERE salary > 10000;TableQuery LanguageRelational Database TablesERDERDFile based system v.s. DBMS•File based system•Database systemTraditional File-Based Systems•Each program defines and manages its own data.•Separation and isolation of data•Duplication of data•Data dependence•Incompatibility of files•Fixed queries of application programDatabase Approach•A shared collection of logically related data, and a description of this data, designed to meet the information needs of an organization.•System catalog (data dictionary)•Program-data independence.File-Based SystemSales FilesData entry & reportFile handling routinesFile definitionThe Database Management System (DBMS)•A software system that enables users to define, create, maintain, and control access to the database.•Data Definition Language(DDL)•Data Manipulation Language (DML)–Structured Query Language (SQL)•Views–Level of security, customization, provide consistent structureComponents of the DBMS Environment•Hardware –Client-server architecture–Backend, front end•Software–DBMS, application programs, SQL•Data–Operational data, meta data•Procedure–Instructions and rules •PeopleRoles in the Database Environment•Data Administrator (DA)–Responsible for the management of the data resource including database planning, development and maintenance of standards, policies, and procedures, and conceptual/logical database design.•Database Administrator (DBA)-more technical–Responsible for the physical realization of the database, including physical database design and implementation, security and integrity of the application users.Roles in the Database Environment (2)•Database Designer–Logical database designer •Identifying the data, relationship between the data, and the constraints on the data.•Business rules.–Physical database designer•Mapping the logical database design into a set of tables and integrity constraints.•Selecting specific storage structures•Designing security measures required on the dataRoles in the Database Environment (3)•Application Developer–Provide the required functionality for the end-users.•End-Users–Naïve users–Sophisticated users.Data RedundancyTypical DBMS Functionality•Define a database : in terms of data types, structures and constraints•Construct or Load the Database on a secondary storage medium•Manipulating the database : querying, generating reports, insertions, deletions and modifications to its content•Concurrent Processing and Sharing by a set of users and programs – yet, keeping all data valid and consistentTypical DBMS FunctionalityOther features:–Protection or Security measures to prevent unauthorized access–“Active” processing to take internal actions on data–Presentation and Visualization of dataAdvantages of DBMS•ClassAdvantages of DBMS (1/2)•Control of data redundancy•Data consistency•More information from the same amount of data•Sharing of data•Improved data integrity•Improved security•Enforcement of standardsAdvantages of DBMS (2/2)•Economy of scale•Balance of confliction requirements•Improved data accessibility and responsiveness•Increased productivity•Improved maintenance through data independence•Increased concurrency•Improved backup and recovery servicesExtending Database Capabilities•New functionality is being added to DBMSs in the following areas:–Scientific Applications–Image Storage and Management–Audio and Video data management–Data Mining–Spatial data management–Time Series and Historical Data ManagementThe above gives rise to new research and development in incorporating new data types, complex data structures, new operations and storage and indexing schemes in database systems.Database Disadvantage•ClassDisadvantages of DBMS•Complexity•Size•Cost of DBMS•Additional hardware costs•Cost of conversion•Performance•Higher impact of a failureWhen not to use a DBMS•Main inhibitors (costs) of using a DBMS:–High initial investment and possible need for additional hardware.–Overhead for providing generality, security, concurrency control, recovery, and integrity functions. •When a DBMS may be unnecessary:–If the database and applications are simple, well defined, and not expected to change.–If there are stringent real-time requirements that may not be met because of DBMS overhead.–If access to data by multiple users is not required.History of DBMS•Apollo moon-landing project (1960s)–GUAM (Generalized Update Access Method)–Hierarchical structure•IMS (Information Management System) (mid 1960s)–Serial storage –device (Tape recorder)•IDS (Integrated Data Store) (mid 1960s)–Network DBMS•CODASYL (Conference on Data Systems Languages)History of