Letter of Information on Business Combination by dwd17416


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									           Chapter 3
Organizing Data and Information

Database: an organized collection of data
Database management system (DBMS):
 group of programs to manage database
  Manipulates database
  Provides an interface between database and the
   user of the database and other application
Database administrator (DBA): skilled IS
 professional who directs all activities related
 to an organization’s database
           The Hierarchy of Data
 Bit (a binary digit): a circuit that    Record: a collection of
  is either on or off                      related data fields
 Byte: eight bits
                                          File: a collection of related
 Character: basic building block
  of information                           records
     Each byte represents a              Database: a collection of
      character                            integrated and related files
     Can be an uppercase letter,
      lowercase letter, numeric digit,    Hierarchy of data: bits,
      or special symbol                    characters, fields, records,
 Field: typically a name, number,         files, and databases
  or combination of characters
  that describes an aspect of a
  business object or activity
The Hierarchy of Data

 Figure 3.1: The Hierarchy of Data
 Data Entities, Attributes, and Keys
 Entity: a generalized class of people, places, or
  things (objects) for which data is collected, stored,
  and maintained
 Attribute: characteristic of an entity
 Data item: value of an attribute
 Key: field or set of fields in a record that is used
  to identify the record
 Primary key: field or set of fields that uniquely
  identifies the record
Data Entities, Attributes, and Keys

        Figure 3.2: Keys and Attributes
       The Database Approach
 Traditional approach to database management:
  separate data files are created for each
   Results in data redundancy (duplication)
   Data redundancy conflicts with data integrity
 Database approach to database management: pool
  of related data is shared by multiple applications
   Significant advantages over traditional approach
   The Database Approach

Figure 3.3: The Database Approach to Data Management
The Database Approach
     The Database Approach

Table 3.2: Disadvantages of the Database Approach
   Data Modeling and the Relational
          Database Model
 When building a database, consider:
   Content: What data should be collected, at what cost?
   Access: What data should be provided to which users and
   Logical structure: How should data be arranged to make
    sense to a given user?
   Physical organization: Where should data be physically
              Data Modeling
Building a database requires two types of
  Logical design
    Abstract model of how data should be structured and
     arranged to meet an organization’s information needs
  Physical design
    Fine-tunes the logical database design for
     performance and cost considerations
               Data Modeling

 Data model: a diagram
  of data entities and
  their relationships
 Entity-relationship
  (ER) diagrams: data
  models that use basic
  graphical symbols to
  show the organization
  of and relationships
  between data
    The Relational Database Model
 Relational model: all data
  elements are placed in two-
  dimensional tables
  (relations), which are the
  logical equivalent of files
 In the relational model
    Each row of a table
     represents a data entity
    Columns of the table
     represent attributes
    Domain: the allowable values
     for data attributes
          Manipulating Data

Figure 3.7: Linking Data Tables to Answer an Inquiry
    Database Management Systems

 Interface between:
   Database and application programs
   Database and the user
 Creating and implementing the right database
  system ensures that the database will support both
  business activities and goals
 DBMS: a group of programs used as an interface
  between a database and application programs or a
  database and the user
       Overview of Database Types
 Flat file
    Simple database program whose records have no
     relationship to one another
 Single user
    Only one person can use the database at a time
    Examples: Access, FileMaker, and InfoPath
 Multiple user
    Allows dozens or hundreds of people to access the same
     database system at the same time
    Examples: Oracle, Sybase, and IBM
Creating and Modifying the Database

 Data definition language (DDL)
    Collection of
     instructions/commands that
     define and describe data and
     data relationships in a database
    Allows database creator to
     describe the data and the data
     relationships that are to be
     contained in the schema
 Data dictionary: a detailed
  description of all the data used
  in the database
          Storing and Retrieving Data
 When an application requests
  data from the DBMS, the
  application follows a logical
  access path
 When the DBMS goes to a
  storage device to retrieve the
  requested data, it follows a path
  to the physical location (physical
  access path) where the data is
   Manipulating Data and Generating
 Query-By-Example (QBE): a visual approach to developing
  database queries or requests
 Data manipulation language (DML): commands that
  manipulate the data in a database
 Structured Query Language (SQL): ANSI standard query
  language for relational databases
 Database programs can produce reports, documents, and
  other outputs
    Database Administration
Database administrator (DBA): directs or
 performs all activities to maintain a database
  Designing, implementing, and maintaining the
   database system and the DBMS
  Establishing policies and procedures
  Employee training
      Popular Database Management
 Popular DBMSs for end users: Microsoft Access and
  FileMaker Pro
 Entire market includes databases by IBM, Oracle, and
 Examples of open-source database systems: PostgreSQL
  and MySQL
 Many traditional database programs are now available on
  open-source operating systems
        Selecting a Database
        Management System
Important characteristics of databases to
  Size of the database
  Cost of the system
  Number of concurrent users
  Ability to be integrated with other systems
  Vendor considerations
  Using Databases with Other
Database management systems are often
 used with other software packages or the
A database management system can act as a
 front-end application or a back-end
  Front-end application: interacts with users
  Back-end application: interacts with applications
  Linking Databases to the Internet

 Linking databases to the Internet is important for many
  organizations and people
 Semantic Web
    Developing a seamless integration of traditional databases with the
    Allows people to access and manipulate a number of traditional
     databases at the same time through the Internet
  Data Warehouses, Data Marts, and
            Data Mining
 Data warehouse: collects
  business information from many
  sources in the enterprise
 Data mart: a subset of a data
 Data mining: an information-
  analysis tool for discovering
  patterns and relationships in a
  data warehouse or a data mart
Data Warehouses, Data Marts, and Data

     Table 3.5: Common Data-Mining Applications
              Business Intelligence
 Business intelligence (BI):        Competitive intelligence: aspect
  gathering the right information     of business intelligence limited
  in a timely manner and usable       to information about competitors
  form and analyzing it to have a     and the ways that knowledge
  positive impact on business         affects strategy, tactics, and
    Turns data into useful           operations
     information that is then
     distributed throughout an
                                     Counterintelligence: steps an
     enterprise                       organization takes to protect
                                      information sought by “hostile”
                                      intelligence gatherers
           Distributed Databases

 Distributed database
   Data may be spread across several smaller databases
    connected via telecommunications devices
   Corporations get more flexibility in how databases are
    organized and used
 Replicated database
   Holds a duplicate set of frequently used data
  Online Analytical Processing
Software that allows users to explore data
 from a number of different perspectives

     Table 3.6: Comparison of OLAP and Data Mining
   Object-Oriented and Object-Relational
      Database Management Systems

Object-oriented database
  Stores both data and its processing instructions
  Method: a procedure or action
  Message: a request to execute or run a method
   Visual, Audio, and Other Database
 Visual databases for storing images
 Audio databases for storing sound
 Virtual database systems: allow different databases to
  work together as a unified database system
 Other special-purpose database systems
    Spatial data technology: stores and accesses data according to the
     locations it describes and permits spatial queries and analysis
               Video Clip
 http://www.youtube.com/watch?v=bWB3kEw08Gk

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