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ระบบฐานข้อมูลขั้นสูง (Advanced Database Systems)

Introduction to ECE613. ระบบฐานข้อมูลขั้นสูง (Advanced Database Systems). Lecturer AJ . Suwan Janin. Phone: 089-148-3993 E-mail: suwanjanin@gmail.com. Outline. Introduction Database Fundamentals Database Management System (DBMS) Prevalent Database Models History of Databases

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ระบบฐานข้อมูลขั้นสูง (Advanced Database Systems)

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  1. Introduction to ECE613 ระบบฐานข้อมูลขั้นสูง(Advanced Database Systems) Lecturer AJ. SuwanJanin Phone: 089-148-3993 E-mail: suwanjanin@gmail.com

  2. Outline • Introduction • Database Fundamentals • Database Management System (DBMS) • Prevalent Database Models • History of Databases • Why Focus on Relational? • Conclusion

  3. Introduction • Why the real world used database? • Today databases are a part of the information technology (IT) industry and business. • Banking transactions, travel reservations, • employment relationships, web site searches, purchases, and most other transactions • Data are recorded in and served by databases.

  4. Database Fundamentals • Properties of a Database • A database is a collection of interrelated data items that are managed as a single unit. • Microsoft Access places the entire database in a single data file. • Oracle Corporation defines their database as a collection of physical files managed their database software product. • Microsoft SQL Server and Sybase define a database as a collection of data items common owner, • Multiple databases managed by single instance of the database management software.

  5. Database Fundamentals (cont.) A database object is a named data structure that is stored in a database. The specific types of database objects supported in a database vary from vendor to vendor and from one database model to another. Database model refers to the way in which a database organizes its data to pattern the real world. The most common database models are presented in “Prevalent Database Models”. A file is a collection of related records that are stored as a single unit by an operating system. Given the unfortunately similar definitions of files and databases.

  6. How can we make a distinction? A number of Unix operating system vendors call their password file a “database” . Understanding of certain characteristics or properties that databases possess that ordinary filesdo not, including the following: • Management by a Database Management System (DBMS) • Layers of data abstraction • Physical data independence • Logical data independence

  7. Database Management System (DBMS) • The Database Management System (DBMS) is software provided by the database vendor. • Software products Microsoft Access, Oracle, Microsoft SQL Server, Sybase, DB2, INGRES. The DBMSprovides all the basic services required to organize and maintain the database, including the following: • Moving data to and from the physical data files as needed. • Managing concurrent data access by multiple users, including provisions to prevent simultaneous updates from conflicting with one another.

  8. Basic Services of DBMS • Managing transactions so that each transaction’s database changes are an all-or-nothing unit of work. In other words, if the transaction succeeds, all database changes made by it are recorded in the database; if the transaction fails, none of the changes it made are recorded in the database. • Support for a query language, which is a system of commands that a database user employs to retrieve data from the database. • Provisions for backing up the database and recovering from failures. • Security mechanisms to prevent unauthorized data access and modification.

  9. Layers of Data Abstraction Figure 1-1 Database layers of abstraction

  10. Prevalent Database Models • Flat Files Figure 1-2 Flat file order system

  11. The Hierarchical Model

  12. The Network Model

  13. The Relational Model

  14. The Object-Oriented Model

  15. A Brief History of Databases Space exploration projects led to many significant developments in the science and technology industries, including information technology. As part of the NASA Apollo moon project, North American Aviation (NAA) built a hierarchical file system named Generalized Update Access Method (GUAM)in 1964. IBM joined NAA to develop GUAM into the first commercially available hierarchical model database, called Information Management System (IMS), released in 1966.

  16. Why Focus on Relational? • Definition, maintenance, and manipulation of data storage structures is easy. • Data is retrieved through simple ad hoc queries. • Data is well protected. • Well-established ANSI (American National Standards Institute) and ISO (International Organization for Standardization) standards exist. • There are many vendors from which to choose. • Conversion between vendor implementations is relatively easy. • RDBMSs are mature and stable products.

  17. Conclusion • This chapter introduces fundamental concepts . • Definitions of the databases, properties common to databases, • Prevalent database models, a brief history of databases. • The rationale for focusing on the relational model.

  18. Q&A??????? THANK YOU FOR YOUR KIND ATTENTION !!! Lecturer AJ. SuwanJanin

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