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Understanding Databases and Data Management Systems

Explore databases, data integrity, data hierarchy, data types, file maintenance, and database management systems. Learn about data models, validation, and various database operations.

gillian-crosby
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Understanding Databases and Data Management Systems

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  1. Objectives Overview See Page 351 for Detailed Objectives Discovering Computers Fundamentals, 2012 Edition Chapter 9

  2. Objectives Overview See Page 351 for Detailed Objectives Discovering Computers Fundamentals, 2012 Edition Chapter 9

  3. Databases, Data, and Information Page 352 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  4. Databases, Data, and Information Pages 352 – 353 Figure 9-1 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  5. Databases, Data, and Information • Database software,often called a database management system(DBMS), allows users to: Page 352 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  6. Databases, Data, and Information • Data integrity identifies the quality of the data • Garbage in, garbage out (GIGO) points out the accuracy of a computer’s output depends on the accuracy of the input Page 353 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  7. Databases, Data, and Information • Valuable information should have the following characteristics: Page 354 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  8. The Hierarchy of Data • Data is organized in layers • Files, records, fields, characters Page 355 Figure 9-2 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  9. The Hierarchy of Data • A character is one byte • Numbers, letters, spaces, punctuation marks, or other symbols • A field is a combination of one or more related characters • Field name • Field size • Data type Pages 355 – 356 Figure 9-3 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  10. The Hierarchy of Data • Common data types include: Page 356 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  11. The Hierarchy of Data • A record is a group of related fields • A primary keyuniquely identifies each record • A data fileis a collection of related records Page 356 Figure 9-4 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  12. Maintaining Data • File maintenancerefers to the procedures that keep data current Pages 357 - 358 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  13. Maintaining Data • Users add new records to a file when they obtain new data Page 357 Figure 9-5 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  14. Maintaining Data • Users modify a record to correct inaccurate data or update old data Pages 357 - 358 Figure 9-6 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  15. Maintaining Data • When a record no longer is needed, a user deletes it from a file Pages 358 - 359 Figure 9-7 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  16. Maintaining Data • Validation compares data with a set of rules or values to find out if the data is correct Pages 359 - 360 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  17. File Processing Versus Databases Pages 361 - 362 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  18. File Processing Versus Databases Page 362 Figure 9-10 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  19. Database Management Systems Page 363 Figure 9-11 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  20. Database Management Systems • A data dictionarycontains data about each file in the database and each field in those files Page 364 Figure 9-12 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  21. Database Management Systems • A DBMS provides several tools that allow users and programs to retrieve and maintain data in the database Pages 364 - 366 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  22. Database Management Systems • A query languageconsists of simple, English-like statements that allow users to specify the data to display, print, or store • Query by example(QBE) provides a GUI to assist users with retrieving data Pages 364 - 366 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  23. Database Management Systems Page 365 Figure 9-13 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  24. Database Management Systems • A form is a window on the screen that provides areas for entering or modifying data in a database Page 366 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  25. Database Management Systems • A report generatorallows users to design a report on the screen, retrieve data into the report design, and then display or print the report Page 366 Figure 9-15 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  26. Database Management Systems Page 367 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  27. Database Management Systems • A DMBS provides a variety of techniques to restore the database to a usable form in case it is damaged or destroyed Page 367 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  28. Relational, Object-Oriented, and Multidimensional Databases • A data modelconsists of rules and standards that define how the database organizes data • A relational databasestores data in tables that consist of rows and columns • Each row has a primary key • Each column has a unique name • A relationship is a link within the data Page 368 Figure 9-17 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  29. Relational, Object-Oriented, and Multidimensional Databases • Structured Query Language(SQL) is a query language that allows users to manage, update, and retrieve data Page 369 Figure 9-18 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  30. Relational, Object-Oriented, and Multidimensional Databases • An object-oriented database (OODB) stores data in objects • Object-oriented databases often use Object Query Language (OQL) to manipulate and retrieve data Page 369 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  31. Relational, Object-Oriented, and Multidimensional Databases • A multidimensional databasecan store data in more than two dimensions of data • Can consolidate data much faster than a relational database • A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions Page 370 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  32. Web Databases • Databases on the Web allow you to: Page 370 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  33. Web Databases Page 371 Figure 9-19 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  34. Video: How a Photo Sharing Site Keeps Its Data CLICK TO START Discovering Computers Fundamentals, 2012 Edition Chapter 9

  35. Database Administration • It is important to have a carefully designed database Page 371 Figure 9-20 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  36. Database Administration Page 371 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  37. Database Administration • Employees should learn how to use the data in the database effectively Page 372 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  38. Summary Page 372 Discovering Computers Fundamentals, 2012 Edition Chapter 9

  39. Chapter 9 Complete

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