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The Database Environment

The Database Environment. IST359 M005. Yang Wang ywang@syr.edu 342 Hinds http://blackboard.syr.edu. Acknowledgements and caveat. These slides draw liberally, with permission, from the following sources: IST359 material s by Prof. Michael Fudge Jr.

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The Database Environment

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  1. The Database Environment IST359 M005 Yang Wang ywang@syr.edu 342 Hinds http://blackboard.syr.edu

  2. Acknowledgements and caveat • These slides draw liberally, with permission, from the following sources: • IST359materials byProf. Michael Fudge Jr. • Caveat (beware): At best, PowerPoint slides are only a pale limitation of the entirety of a class meeting. In IST359 in particular, the lectures will cover topics beyond what appears in these slides. Don’t rely on them as a substitute for attending class.

  3. Teaching Assistant Zhiheng Mai zmai@syr.edu

  4. Learning Objectives • Concretize the concepts of data, information, data management and metadata • Explain what a database is and why databases are important • Describe a database management system • Differentiate between the DBMS and a database • Describe the different data models and abstraction layers • Explain the similarities and differences among DBMS products • Explain DBMS history and modern uses • Describe how data is physically stored in primary and secondary storage

  5. Before we begin…What’s…

  6. Data or Information?

  7. Where’s theData?Where’s the Metadata?

  8. Where is the:Data?Meta-Data?

  9. Activity: Data or Meta-Data? • A Zip Code: 13244 • A Zip Code is 5 Characters XXXXX • A List of First Names: Tom, Dick, Harry • A Picture, Like This One: • The Name of the Picturefile FrostTrees.jpg • When you place an order, the quantity of the item ordered must be a number >0

  10. Somethingstrangeand confusing: • Data can be information: • $5 (the amount of money in my wallet) • Information can be data: • I calculate student final grades, then place them on a form sent to the registrar’s office. • Metadata can be data: • The names of MP3 files in your personal collection. Actually it’s all about context!

  11. What is it, part duex!

  12. Elements of a Database Database Data-Management Meta-Data Data “In” Data Information “Out” End-User DBMS is software. It stores the data/meta data and “enables” data-management

  13. Clarification via Family Guy • Brian can write his novel on a typewriter or w/pen and paper. • But there are obvious advantages to using word processing software. • Most databases use DBMS’s just like most papers are written with word processors Database Brian’s Novel DBMS  WP Software

  14. Is this: Database or DBMS?

  15. Database or DBMS?

  16. Database or DBMS?

  17. SQL Server: Database or DBMS?

  18. Database or DBMS?

  19. Database or DBMS?

  20. Database or DBMS?

  21. Fundamental Axioms of DBMSs • Users communicate with computer apps • Computer apps communicate with DBMSs • Users normally do not communicate with DBMSsdirectly • Normally DBMSs are not used interactively • A DBMS is not a replacement for sound database design principles.

  22. First of many examples for the semester • https://my.ischool.syr.edu Website Db using Relational Model You Web Server (IIS) Web Browser SQL Server User Interface and Business Logic (HTML/C#) Data access logic and Data (SQL) ApplicationComponents

  23. Data or Metadata? Database? DBMS?

  24. Evolution of DBMSs

  25. Enterprise DBMS Market Share * Source: Computerworld 2007

  26. DBMS deployment plans 2008 * source: gartner

  27. An employable skill in the future. Source BLS: 2008http://www.bls.gov/oes/current/oes151061.htm

  28. Data Models: Abstraction Levels Conceptual Highly AbstractHardware and Software Independent Logical Somewhat Abstract Hardware Independent Software Dependent Internal External Not Abstract (Concrete)Hardware and Software Dependent Physical

  29. An Concrete Example • SU administration asks us to build a database for class enrollment • Conceptual model: represent requirements, what needs to be represent in the database? • E.g., student info, class info, a student enrolls in a class • Logicalmodel: what database model to use? Relational, object-oriented, object-relational, etc. • E.g., we use relational model (entities, relations). • Internalmodel: use a DBMS to implement our relational model • E.g., what do the student, class tables look like? • Externalmodel: what the internal model looks like to end users (hide details of the implementation, e.g., tables) • E.g., you can see a student enrolls in a class • Physical model: how database is implemented by the DBMS • E.g., how is the database physically stored? In a single file?

  30. Elements of the DBMS Approach • Enterprise Data Model • Graphical model showing high-level entities and relationships for the organization • Relational Databases • Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships • Use of Internet Technology • Networks and telecommunications, distributed databases, client-server and 3-tier architectures • Database Applications • Application programs used to perform database activities CRUD for database users

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