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Database

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  • 1. Database Management An Introduction
  • 2. Goals For Today:
    • Describe why databases have become so important to modern organizations
    • Describe what database and database management systems are and how they work.
    • Explain four emerging database trends:
      • (1) client / server computing,
      • (2) object-oriented databases,
      • (3) data mining, and
      • (4) integrating Web applications
  • 3. Database Defined
    • Database:
      • A collection of related data organized in a way that facilitates data searches.
    • What are some examples of Databases?
  • 4. Example of a Student Database Types of Data Collected in a Typical Student Database
  • 5. Databases Before the Use of Computers
    • Data was stored in:
      • books
      • ledgers
      • card files
      • folders
      • file cabinets
      • or simply in people’s heads!?
  • 6. Computers make the process of storing and managing data easier
  • 7. The Database Approach
    • Database Management System
      • software application which allows you to create, store, organize, and retrieve data from a single database or many databases.
      • Example: MS Access
    • Entity
      • something you collect data about
      • Examples: people or classes
  • 8. A Database Contains the Following:
    • Tables
      • how entities are represented in a database, where each row is a record and each column a field.
    • Fields
      • individual pieces of information
    • Record
      • collection of related fields within one entity
  • 9. Sample Data Table (page 2-94 in your book)
  • 10. Key Database Issues and Activities
    • Entering and Querying Data
    • Creating Database Reports
    • Data Structure
    • Data Type
  • 11. Entering Data
    • Data Entry:
      • process of getting information into a database
      • possible methods of data entry:
        • Data Entry Professional, Electronic Files, Historical Records, or Web Based (Forms)
  • 12. Querying Data
    • Querying:
      • how we get information from a database
    • Structured Query Language (SQL):
      • most common language used to interface with databases
      • Example:
        • SELECT DISTINCTROW STUDENT_ID, GRADE
        • FROM GRADES
        • WHERE GRADE = “A”
        • ORDER BY STUDENT_ID;
  • 13. Querying Data continued
    • Query By Example (QBE)
      • enables you to fill out a grid, or template, in order to construct a description of the data you would like to retrieve.
  • 14.  
  • 15. Creating Database Reports
    • Report:
      • A compilation of data from the database that is organized and produced in a printed format.
      • Typically produced on paper, but also can be displayed on-screen.
      • Example: Quarterly Sales Report
  • 16. Data Structure
    • Database has two parts:
      • Data
      • Data Structure: how the data is organized.
    • Data Model:
      • representation of entities and their relationships to the real world
    • Primary Key:
      • a unique identifier in the database
      • one or more fields
  • 17. Data Structure continued Primary Key is Student ID
  • 18. Data Type
    • Data Type:
      • each field in the database needs to be of a certain type
      • Examples: text, number, dates
    • Data Dictionary:
      • a document (often published online) prepared by the database designers to aid users in data entry.
  • 19. Data Dictionary Example:
    • Students Table
    • Primary Key Field Name Field Type Field Length
    • yes Student ID Number 9
    • no Last Name Text 20
    • no First Name Text 15
  • 20. Database Management Systems Approaches
    • The Hierarchical Model
    • The Network Model
    • Relational Model
    • Normalization
    • Associations
  • 21. The Hierarchical Model
    • Records in parent entities can have many child records, but each child can have only one parent.
    Parent Child
  • 22. The Network Model
    • In this case you can have multiple children and parents
    Parents Children
  • 23. The Relational Model
      • A good relational database design eliminates unnecessary data duplications and is, therefore, easier to maintain
      • Relationship: joining two tables on a common field
    Relationship
  • 24. Normalization
    • A technique used to make complex databases more efficient and easier to handle
    • Eliminates Redundant Data
  • 25. Normalization continued Database w/redundant data
  • 26. Database after Normalization
  • 27. Three Types of Associations or Relationships
      • One-to-One
        • Each team has only one home stadium, and each home stadium has only one team
          • Team ID Team Name Location Stadium ID
      • One-to-Many
        • Each Player is on only one team, but each team has many players
          • Player ID Player Name Position Team ID
      • Many-to-Many
        • Each player participates in many games, and each game has many players
          • Team 1 Team 2 Date Player ID Points Minutes Fouls
  • 28. Recent Developments Affecting Database Design and Use
    • Databases and Client / Server Computing
    • Object-Oriented Databases
    • Data Mining
    • Linking Web Site Applications to Organizational Databases
  • 29. Databases and Client / Server Computing
    • Database application is divided into two parts:
      • Database Server
        • where all data is stored on a powerful machine
      • PC Client
        • the program used to manipulate the data resides on an individual user’s computer
  • 30. Object-Oriented Databases
    • treat tables, queries, and other components as generic reusable OBJECTS (rather than data) that can be mixed and matched and used in many applications (e.g. MS Excel and MS Access).
    • Most of today’s database applications have some of these Object characteristics.
  • 31. Data Mining
    • Allows companies to sort and analyze information to better understand customers, products, markets, or any other phase of their business for which data has been captured.
    • Example: Grocery Store Club Cards
  • 32. Data Mining continued
    • Data Warehouses
      • An integration of multiple, large databases and other information sources into a single repository or access point that is suitable for direct querying, analysis, or processing
  • 33. Data Warehouse Examples
    • TELECOMMUNICATIONS REPRESENTATIVE COMPANIES
    • Analysis of the following: AT&T
    • Call volumes Ameritech
    • Equipment sales Belgacom
    • Customer profitability British Telecom
    • Costs Telestra AustraliaTelecom Ireland
    • Inventory Telecom Italia
    • Purchasing leverage with suppliers
    • Frequent buyer program management
  • 34. Data Mining continued
    • Data Marts
      • A small-scale data warehouse that contains a subset of the data for a single aspect of a company’s business
      • Examples: finance, inventory, or personnel
  • 35. Linking Web Site Applications to Organizational Databases
    • Example:
      • many comapies are enabling users of their Web Site to:
        • view product catalogs,
        • check inventory, and
        • place orders
      • these are all actions that read and write to the organizations’ databases.
  • 36. Goals For Today:
    • Described why databases have become so important to modern organizations
    • Described what database and database management systems are and how they work.
    • Explained four emerging database trends:
      • (1) client / server computing,
      • (2) object-oriented databases,
      • (3) data mining, and
      • (4) integrating Web applications

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