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CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
CSC1100 - Chapter08 - Database Management
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CSC1100 - Chapter08 - Database Management

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အချက်အလက်အစုစီမံခန့်ခွဲမှု

အချက်အလက်အစုစီမံခန့်ခွဲမှု

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  • 1. Discovering Computers 2008 Chapter 08 Database Management
  • 2. Chapter 08 Objectives Differentiate between a file processing Define the term, database system approach and the database approach Identify the qualities Discuss the functions of valuable information common to most DBMSs Describe characteristics of Explain why data is important relational, object-oriented, and to an organization multidimensional databases Discuss the terms character, Explain how to interact with Web databases field, record, and file Discuss the responsibilities of Identify file maintenance techniques database analysts and administrators Next
  • 3. Data and Information What is a database? Collection of data Database software organized so Database software also called database you can access, allows you to management system retrieve, and (DBMS) use it Create Create forms database and Add, Sort reports change, and and delete retrieve data data Nextp. 514 - 515
  • 4. Data and Information How are data and information related? Data is a collection of unprocessed items Information is data that is organized and meaningful Computers process data into information Nextp. 514 - 515 Fig. 10-1
  • 5. Data and Information What is data integrity? Degree to which data is Garbage in correct Garbage in, garbage out (GIGO)—computer phrase that means you cannot create correct Garbage out information from incorrect data Data integrity is lostClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickData Security below Chapter 10 Next p. 516
  • 6. Data and Information What are the qualities of valuable information? Accurate Verifiable Timely Organized Accessible Useful Cost-effective Nextp. 516 - 517
  • 7. The Hierarchy of Data What is a hierarchy? Database contains files, file contains records, record contains fields, field contains characters Nextp. 517 Fig. 10-2
  • 8. The Hierarchy of Data What is a field? Combination of one or more characters Smallest unit of data user accesses Field name uniquely identifies each field Field size defines the maximum number of characters a field can contain Data type specifies kind of data field contains Nextp. 518 Fig. 10-3
  • 9. The Hierarchy of Data What are common data types? Text Numeric AutoNumber (also called numbers unique number automatically alphanumeric)—letters, only assigned to each new record numbers, or special characters Currency Date Memo dollar and cent amounts or month, day, year, and lengthy text entries numbers containing decimal sometimes time values Object Yes/No Hyperlink (also called BLOB for binary large (also called Web address that links to object)—photograph, audio, video, Boolean)—only the document or Web page or document created in other values Yes or No (or application such as word True or False) processing or spreadsheet Nextp. 518
  • 10. The Hierarchy of Data What is a record? Group of related fields Key field, or primary key, uniquely identifies each record Nextp. 519
  • 11. The Hierarchy of Data What is a data file? Collection of related records stored on disk Member ID First Name Last Name Address City State 2295 Milton Brewer 54 Lucy Court Shelbyville IN 2928 Shannon Murray 33099 Clark Street Montgomery AL 3876 Louella Drake 33 Timmons Place Cincinnati OH 3928 Adelbert Ruiz 99 Tenth Street Carmel IN 4872 Elena Gupta 2 East Penn Drive Pittsboro IN records key fields field Nextp. 518 – 519 Fig. 10-4
  • 12. Maintaining Data What is file maintenance? Procedures that keep data current Adding records Changing records Deleting records Nextp. 520
  • 13. Maintaining Data Why do you add records? Add new record when you obtain new data Nextp. 520 Fig. 10-5
  • 14. Maintaining Data Why do you change records? Correct inaccurate data Update old data Nextp. 521 Fig. 10-6
  • 15. Maintaining Data Why do you delete records? When record no longer is needed Some programs remove record immediately, others flag record Nextp. 522 Fig. 10-7
  • 16. Maintaining Data What is validation? Process of comparing data with a set of rules to find out if data is correct Reduce data entry errors and enhance data integrity before program writes data on disk Nextp. 522 - 523 Fig. 10-8
  • 17. Maintaining Data What are the types of validity checks? Check Digit Alphabetic/ Completeness number(s) or Numeric Check Check character(s) ensures correct verifies that a appended to or type of data required field inserted into a entered contains data primary key value to confirm Consistency Range Check accuracy of Check determines primary key value tests for logical whether number is within specified relationship range between two or more fields Nextp. 523
  • 18. File Processing Versus Databases What is a file processing system? Each Records in one department or file may not area within May have relate to organization weaknesses records in any has own set of other file files Data Isolated redundancy— data—data same fields stored in stored in separate files multiple files so it is difficult to access Nextp. 524
  • 19. File Processing Versus Databases What is the database approach? Many programs and users can share data in database Secures data so only authorized users can access certain data Nextp. 524 - 525 Fig. 10-9
  • 20. File Processing Versus Databases What are the strengths of the database approach? Reduced data redundancy Improved data integrity Shared data Easier access Reduced development time Nextp. 525
  • 21. File Processing Versus Databases How do a database application and a file processing application differ in the way they store data? Nextp. 525 Fig. 10-10
  • 22. Database Management Systems What are popular database management systems (DBMSs)?Click to view WebLink, click Chapter 10,Click Web Link from leftnavigation, then clickMySQL below Chapter 10 Next p. 526 Fig. 10-11
  • 23. Database Management Systems What is a data dictionary? Contains data about each file in database and each field within those files Nextp. 527 Fig. 10-12
  • 24. Database Management Systems What is a query? Request for specific data from a database Query language consists of simple, English-like statements that allow users to specify data to display, print, or storeClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickQuerybelow Chapter 10 Next p. 528 - 529 Fig. 10-13
  • 25. Database Management Systems What is a query by example (QBE)? Program retrieves records that match criteria entered in form fields Has a graphical user interface that assists users with retrieving data Nextp. 528 - 529 Fig. 10-14
  • 26. Database Management Systems What is a form? Window on screen that provides areas for entering or changing data in database Used to retrieve and maintain data in a database Form that sends data across network or Internet is called e-form, short for electronic form Nextp. 530 Fig. 10-15
  • 27. Database Management Systems What is a report generator? Allows user to design a report on screen, retrieve data into report design, then display or print reports Also called report writer Nextp. 530 Fig. 10-16
  • 28. Database Management Systems What is data security? Access privileges DBMS provides define activities means to ensure that specific user only authorized or group of users users can access can perform data Read-only Full-update privileges - privileges - user can user can view data, view and but cannot change data change it Nextp. 530 - 531
  • 29. Database Management Systems What are backup and log? Backup is a copy of the entire database Log is a listing of activities that change database contents DBMS places three items in log: before image, actual change, and after image Nextp. 531 Fig. 10-17
  • 30. Database Management Systems Video: How A Photo Sharing Site Keeps its Data CLICK TO START Next
  • 31. Database Management Systems What is a recovery utility? Uses logs and/or backups to restore Rollforward—DBMS database when it is uses log to re-enter damaged or destroyed changes made to data- base since last save or backup Rollback—DBMS uses Also called forward log to undo any changes recovery made to database during a certain period of time Also called backwardClick to view Web recoveryLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickContinuous Backupbelow Chapter 10 Next p. 531 - 532
  • 32. Object- Relational, Object-Oriented, and Multidimensional Databases What is a data model? Rules and standards that define how database organizes data Defines how users view organization of data Four popular data models Relational Object-oriented Object-relational Multidimensional Nextp. 532 Fig. 10-18
  • 33. Object- Relational, Object-Oriented, and Multidimensional Databases What is a relational database? Stores data in tables that consist of rows and columns Each row has primary key Each column has unique name Stores data relationships Uses specialized terminologyClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickRelational Databases belowChapter 10 Next p. 533 Fig. 10-19
  • 34. Object- Relational, Object-Oriented, and Multidimensional Databases What is a relationship? Connection within data Nextp. 533 Fig. 10-20
  • 35. Object- Relational, Object-Oriented, and Multidimensional Databases What is Structured Query Language (SQL)? Allows you to manage, update, and retrieve data Has special keywords and rules included in SQL statementsClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickSQL below Chapter 10 Next p. 534 Fig. 10-21
  • 36. Object- Relational, Object-Oriented, and Multidimensional Databases What is an object-oriented database (OODB)? Object is item that contains data, Stores data in objects as well as actions that read or process data Can store more types of data Advantages Can access data faster Programmers can reuse objects Often uses object query language (OQL)Click to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickObject-Oriented Databasesbelow Chapter 10 Next p. 534 - 535
  • 37. Object- Relational, Object-Oriented, and Multidimensional Databases What are examples of applications appropriate for an object-oriented database? Multimedia databases Groupware databases Store images, audio clips, Store documents such as and/or video clips schedules, calendars, manuals, memos, and reports Computer-aided design (CAD) databases Hypertext databases Store data about Contain text links engineering, architectural, to other documents and scientific designs Hypermedia databases Web databases Contain text, graphics, Link to e-form on Web page video, and sound Nextp. 534
  • 38. Object- Relational, Object-Oriented, and Multidimensional Databases What is a multidimensional database? Stores data in dimensions Multiple dimensions, also called hypercube, allow users to analyze any view of data Can consolidate data much faster than relational databaseClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickMultidimensional Databasesbelow Chapter 10 Next p. 535
  • 39. Object- Relational, Object-Oriented, and Multidimensional Databases What is a data warehouse? Huge database system that stores and manages data required to analyze historical and current transactions Quick and efficient Often uses a process called data way to access large mining to find patterns and amounts of data relationships among data Uses multidimensional Data mart is smaller databases version of data warehouse Nextp. 536
  • 40. Web Databases What is a Web database? Database you access through the Web by filling in a form on a Web page Usually resides on a database server, a computer that stores and provides access to a databaseClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickCollaborative Databasesbelow Chapter 10 Next p. 536 - 537 Fig. 10-23
  • 41. Database Administration What are guidelines for developing a database? 1. Determine the purpose of the database 2. Design the tables 3. Design the records and fields Design tables on paper first for each table Each table should contain Be sure every record has a unique data about one subject primary key Use separate fields for logically distinct items Do not create fields for information 4. Determine the that can be derived from entries in other fields relationships among Allow enough space for each field the tables or files Set default values for frequently entered data Nextp. 537 Fig. 10-24
  • 42. Database Administration What is the role of the database analyst and administrator? Database analyst (DA) Database administrator Focuses on meaning and (DBA) usage of data Creates and maintains data Decides proper placement dictionary, manages of fields, defines database security, relationships, and monitors database identifies users’ access performance, and checks privileges backup and recovery proceduresClick to view WebLink, click Chapter 10, ClickWeb Link from leftnavigation, then clickDatabase Administrators belowChapter 10 Next p. 538
  • 43. Summary of Database Management How data and information are valuable assets to an organization Advantages of organizing data in a database Methods for maintaining high-quality data Various types of databases Assessing the quality of valuable information Role of the database analysts and administratorsChapter 08Complete

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