Storing%20Organizational%20Information%20-%20Databases

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CHAPTER 7

• Storing Organizational Information - Databases

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Learning Outcomes

• Define the fundamental concepts of the relational
  database model
• Evaluate the advantages of the relational
  database model
• Compare operational integrity constraints and
  business-critical integrity constraints
• Describe the role and purpose of a database
  management system
• List and describe the four components of a
  database management system
• Describe the two primary methods for integrating
  information across multiple databases

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Overview

• Information is stored in databases
• Database maintains information about various
  types of objects (inventory), events
  (transactions), people (employees), and places
  (warehouses)

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Database Models

• Hierarchical database stores related
  information in terms of predefined categorical
  relationships in a tree-like fashion
• Network database used by a network installation
  tool to allocate and track network resources
• Relational database model stores information in
  the form of logically related two-dimensional
  tables

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Entities, Entity Classes, and Attributes

• Entity a person, place, thing, transaction, or
  event about which information is stored
• The rows in each table contain the entities
• Entity includes Daves Sub Shop and Pizza Palace
  entities Figure 2.6 CUSTOMER
• Entity class (table) a collection of similar
  entities
• Entity classes include CUSTOMER, ORDER, ORDER
  LINE, DISTRIBUTOR, and PRODUCT
• Attributes (fields, columns) characteristics or
  properties of an entity class
• The columns in each table contain the attributes
• Attributes for CUSTOMER include Customer ID,
  Customer Name, Contact Name, and Phone

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Keys and Relationships

• Primary key a field (or group of fields) that
  uniquely identifies a given entity in a table
• Foreign key a primary key of one table that
  appears an attribute in another table and acts to
  provide a logical relationship among the two
  tables

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A relational database for Coca-Cola
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Relational Database Advantagesfrom a business
perspective

• Increased flexibility
• Increased scalability and performance
• Reduced information redundancy
• Increased information integrity (quality)
• Increased information security

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Increased Flexibility

• A well-designed database should
• Handle changes quickly and easily
• Provide users with different views
• A database has only one physical view
• Physical view deals with the physical storage
  of information on a storage device such as a hard
  disk
• A database can have multiple logical views
• Logical view focuses on how users logically
  access information to meet particular business
  needs

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Increased Scalability and Performance

• A database must scale to meet increased demand,
  while maintaining acceptable performance levels
• Scalability refers to how well a system can
  adapt to increased demands
• Performance measures how quickly a system
  performs a certain process or transaction

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Reduced Information Redundancy

• Databases reduce information redundancy
• Redundancy the duplication of information or
  storing the same information in multiple places
• Inconsistency is one of the primary problems with
  redundant information

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Increase Information Integrity

• Information integrity a measure of the quality
  of information
• Integrity constraints rules that help ensure
  the quality of information
• Operational integrity constraints rules that
  enforce basic and fundamental information-based
  constraints
• Business-critical integrity constraints rules
  that enforce business rules vital to an
  organizations success and often require more
  insight and knowledge than operational integrity
  constraints

Product returns are not accepted for fresh
product 15 days after purchase
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Increased Information Security

• Information is an organizational asset and must
  be protected
• Databases offer several security features
  including
• Passwords provide authentication of the user
• Access levels determine who has access to the
  different types of information
• Access controls Determine types of user access,
  such as read-only access

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Database management systems (DBMS) software
through which users and application programs
interact with a database
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Four components of a DBMS
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Data Definition Component

• helps create and maintain the data dictionary
  and the structure of the database
• Data dictionary a file that stores definitions
  of information types, identifies the primary and
  foreign keys, and maintains the relationships
  among the tables
• The data dictionary essentially defines the
  logical properties of the information that the
  database contains

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Data Manipulation Component

• Data manipulation component allows users to
  create, read, update, and delete information in a
  database
• A DBMS contains several data manipulation tools
• Views Allows users to see, change, sort, and
  query the database content
• Report generators
• Query-by-example (QBE)
• Structured query language (SQL)

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Application Generation and Data Administration
Components

• Application generation component includes tools
  for creating visually appealing and easy-to-use
  applications
• Data administration component provides tools
  for managing the overall database environment by
  providing faculties for backup, recovery,
  security, and performance
• IT specialists primarily use these components

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Integrating Information among Multiple Databases

• Organizations typically maintain multiple
  systems, each with its own database
• Integration allows separate systems to
  communicate directly with each other
• Forward integration takes information entered
  into a given system and sends it automatically to
  all downstream systems and processes
• Backward integration takes information entered
  into a given system and sends it automatically to
  all upstream systems and processes

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Building a central repository specifically for
integrated information
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Opening Case Study Questions - Searching for
Revenue - Google

1. Identify the different types of entity classes
   that might be stored in Googles indexing
   database
2. Explain why database technology is so important
   to Googles business model
3. Explain the difference between logical and
   physical views and why logical views are
   important to Googles employees