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Database Systems

Database Systems. Department of Information Technology. Database Systems – week 1. 0. Introduction 1. Database Concepts. 0.1 Aims or Objectives. Fundamental of relational database; Understanding in relational data model; Knowledge and skills in the use of relational DBMS and PosterSQL

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Database Systems

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  1. Database Systems Department of Information Technology

  2. Database Systems – week 1 0. Introduction 1. Database Concepts

  3. 0.1 Aims or Objectives • Fundamental of relational database; • Understanding in relational data model; • Knowledge and skills in the use of relational DBMS and PosterSQL • Knowledge of database design.

  4. 0.2 What does it cover? • Idea of database approaches (week 1-2); • Relational model and relational database management systems (weeks 2-4); • Database languages and programming (4-7) • (Relational) Database design (weeks 8-10) • Others: database administration, advanced databases etc. (weeks 11-12)

  5. Tutorials Lecture Lab 0.3 Learning Strategy

  6. Guided reading of the text book A) T. M. Connolly, C. E. Begg, Database Systems: A Practical Approach to Design, Implementation, and Management (Fourth Edition), Addison-Wesley, 2004. ISBN: 0-321-21025-5, URL:http://www.booksites.net/connolly B) Eaglestone.BM, Relational Databases, Stanley Thornes,1991. 0.3 Learning Strategy

  7. 0.4 Learning Assessment • A) Course work (20%) • SQL Lab Test (10%): Week 10. • Database Design (10%): Week 10. • B) Exam (80%): Jan 2007.

  8. 0.5 Teaching Team • Lecturers: • Teaching Assistants:

  9. 1.1 What is a Database System? Scenario: You are a book shop owner. • Readers buy books from you; • Readers can order books from you; • Readers can rent books from you. • Needs • if a book (how many copies) is available? • Which book has this reader rented? • If it is overdue? • Which book has this reader ordered? • When will a ordered book become available?

  10. 1.1 What is a Database System? 1. What Information do you need to for managing your book shop? 2. What management activities are involved? 3. How to design a computer system to help the staff to manage all the activities?

  11. 1.1 What is a Database System? 1. Information needed: • Books (authors, title, price); • Readers (name, address, telephone, ordered book, books rent) • Books in shop; • Books on order;

  12. 1.1 What is a Database System? 2. Management activities 1) To check the availability of a book; 2) If this book is on order? 3) How many book has a reader rent? 4) If there is any book overdue? 5) The charge to rent or buy a book 6) ……

  13. Book_Title Name Authors Address Telephone Published date Price Eric Relational Databases BEA Leeds 2000.5 0113- 12.35 Java Peter Bradford EFH 01274- 2001.2 16.50 1.1 What is a Database Books: Readers: Any More…….?

  14. 1.2 How to implement the Database Management Interaction between Data and Programs Data Program User

  15. 1.3 Conventional Approach File-oriented: • Data: represented in a convenient form. Database, BEA, 2000.5, 12.5 Jave, EFH, 2001.2, 16.5 ………… • Need to design the data files for a specific activity; • Database does not exist as a single structure, • Database is distributed across a number of files.

  16. DB2 DB1 Program DB3 DB4 1.3 Conventional Approach Programs are central, need to know: • how the files are organized? • how records may be accessed, and the meaning of data? As a result, • Expensive to develop/maintain the system • Difficult in Manage Data.

  17. Book_Title Authors Published date Price Databases BEA 2000.5 12.35 Java EFH 2001.2 16.50 1.4 Database Approach Database-oriented: • Data: represented in table form. • Database is central –designed and managed in its own right, by Database administrator (DBA). • Programs are designed around the database.

  18. User2 User1 Database User4 User3 1.5 What is a Database • Database management system (DBMS): a type of computer program, which is used to manage data stored on a computer; • DBMS aims to enable other programs and users to make use of that data.

  19. 1.5 What is a Database Relational DBMS - (RDBMS) • one of the wide used and the easies to operate database systems. • Relational data model – the basis of RDBMS.

  20. Warehouse_No Location WH1 Leeds WH2 Bradford 1.5 What is a Database Relational DBMS - RDBMS: • theoretical foundation – relational model. • Logical data structure - Table. • a table has a name and is made up of named columns of data. Each row contains one value per column.

  21. 1.6 RDBMS Architecture Relational DBMS

  22. Database 1.6 Advantage and Cost of a Database Approach ????? ?!?! Program

  23. Database 1.6 Advantage and Cost of a Database Approach • Advantages: 1) without affecting the users. • Database may be tuned; • Database can be updated; 2) Data may be shared by many applications/users; 3) Greater security and integrity: • the data is collected together, • the data is managed by database administrator (DBA)

  24. Database 1.6 Advantage and Cost of a Database Approach 4) Greater productivity - easier and faster to create applications programs - NO need to include details of how the data are physically stored; - NOT necessary to change applications programs when the database is changed; - NO need to be re-store the data for new applications.

  25. 1.6 Advantage and Cost of a Database Approach • Costs: 1) requires more hardware resources - a minimum requirement in order to run the DBMS. 2) additional software is required to support the database approach - need extend programming languages. 3) Cost of employing DBA team.

  26. 1.7 Your Homework

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