Sunday, April 19, 2015

CHAPTER 6

FOUNDATION OF BUSINESS INTELLIGENCE: DATABASES AND INFORMATION MANAGEMENT


ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

File organization concepts

• Record: Group of related fields
• File: Group of related files 
• Field: Group of characters as word(s) or number
        - Describes an entity (person, place, thing on which we store information
       - Attribute: Each characteristic, or quality, describing entity
       - Example: Attributes Date or Grade belong to entity Course

  The Data Hierarchy

A computer system organizes data in a hierarchy that starts with the bit, which represents either a 0 or a 1. Bits can be grouped to form a byte to represent one character, number, or symbol. Bytes can be grouped to form a field, and related fields can be grouped to form a record. Related records can be collected to form a file, and related files can be organized into a database.

Problems with the traditional file processing (filesmaintained separately by different departments)

Data redundancy: Presence of duplicate data in multiple files. - Data inconsistency: Same attribute has different values
- Program-data dependence:
           •When changes in program requires changes to data accessed by program
      - Lack of flexibility
      - Poor security
      - Lack of data sharing and availability

     THE DATABASE APPROACH TO DATA MANAGEMENT

 •Database:
Collection of data organized to serve many applications by centralizing data and controlling    redundant data

Database management system:
Interfaces between application programs and physical data files
- Separates logical and physical views of data
- Solves problems of traditional file environment
           i) Controls redundancy
          ii) Eliminated inconsistency
         iii) Uncouples programs and data
         iv) Enables central management and security


     •Relational DBMS
     - Represent data as two-dimensional tables called relations or files
     - Each table contains data on entity and attributes

     •Table: Grid of columns and rows
     Rows (tuples): Records for different entities
     - Fields (columns): Represents attribute for entity
     - Key field: Field used to uniquely identify each record
     - Primary key: Field in table used for key fields
   - Foreign key: Primary key used in second table as look-up field to identify records from original table  

     •Operations of a Relational DBMS: Three basic operations used to develop useful sets of data
       i) SELECT: Creates subset of data of all records that meet stated criteria
      ii) JOIN: Combines relational tables to provide user with more information than available in individual tables
      iii) PROJECT: Creates subset of columns in table, creating tables with only the information specified

     •Capabilities of Database Management Systems
     - Data definition capability: Specifies structure of database content,used tcreate tables and   define characteristics of fields.
     - Data dictionary: Automated or manual file storing definitions of data elements and their       
       characteristics.
     - Data manipulation language: Used to add, change, delete, retrieve data from database
          •Structured Query Language (SQL)
          •Microsoft Access user tools for generation SQL
    - Many DBMS have report generation capabilities for creating polished reports
      (Crystal Reports)

     •Designing Databases
      - Conceptual (logical) design: abstract model from business perspective
      - Physical design: How database is arranged on direct-access storage devices

      •Design process identifies
       - Relationships among data elements, redundant database elements
       - Most efficient way to group data elements to meet business requirements,           
         needs of application programs

      •Normalization
      - Streamlining complex groupings of data to minimize redundant data elements 
        and awkward many-to-many relationships

      •Business intelligence infrastructure
       - Today includes an array of tools for separate systems, and big data

     • Contemporary tools-

       i) Data warehouses:
          •Stores current and historical data from many core operational transaction systems
          •Consolidates and standardizes information for use across enterprise, but data 
           cannot be altered
          •Data warehouse system will provide query, analysis, and reporting tools

       ii) Data marts:
           •Subset of data warehouse with summarized or highly focused portion of firm’s data for   
            use by specific population of users
          •Typically focuses on single subject or line of business

      iii) Hadoop:
          • Enables distributed parallel processing of big data across inexpensive computers.
          • Key services
              - Hadoop distributed file system (HDFS): data storage
              - Mapreduce: breaks data into clusters for work
              - Hbase: NoSQL database
          • Used by Facebook, Yahoo, NexBio

       iv) In-memory computing:
          • Used computers main memory (RAM) for data storage to avoid delays in retrieving data         from disk storage.
          • Used in big data analysis.
          • Can reduce hours/days of processing to seconds 
          • Requires optimized hardware.

       v) Analytical platforms:
- High-speed platforms using both relational and non-relational tools optimized for large datasets. 


•Analytical tools: Relationships, patterns, trends
- Tools for consolidating, analyzing, and providing access to vast amounts of data to help 
   users make better business decisions.

i) Multidimensional data analysis (OLAP):
 - Online analytical processing (OLAP)
   •Supports multidimensional data analysis
   •Enables viewing data using multiple dimensions
    •Each aspect of information (product, pricing, cost, region, time period) is 
     different dimension
   •Example: How many washers sold in East in June compared with others 
     regions? 
 - OLAP enables rapid, online answers to ad hoc queries

ii) Data Mining: 
  -Finds hidden patterns, relationships in large databases
  -Infers rules to predict future behavior
  -The patterns and rules are used to guide decision making and forecast the
   effect of those decisions
  -Popularly used to provide detailed analyses of patterns in customer data for 
   one-to-one marketing campaigns or to identify profitable customers.
  -Less well known: used to trace calls from specific neighborhoods that use 
   stolen cell phones and phone accounts.
   - Types of information obtainable from data mining:
      •Associations: Occurrences linked to single event
      •Sequences: Events linked over time
      •Classification: Recognizes patterns that describe group to which item    
        belongs
      •Clustering: Similar to classification when no groups have been defined;    
        finds groupings within data
      •Forecasting: Uses series of existing values to forecast what other 
       values will be

iii) Text Mining:
   - Extracts key elements from large unstructured data sets.
     • Stored e-mails
     • Call center transcripts
     • Legal cases
     • Patent descriptions
     • Service reports, and so on
   - Sentiment analysis software
     • Mines e-mails, blogs, social media to detect opinions.

iv) Web Mining:
   - Discovery and analysis of useful patterns and information from web.
     • Understand customers behavior.
     • Evaluate effectiveness of web site, and so on.
   - Web content mining.
     • Mines content of Web page
   - Web structure mining
     • Analyzes links to and from web page
   - Web usage mining
     • Mines user interaction data recorded by web serve.

v) Databases and the Web
   - Many companies use Web to make some internal databases available to customers or partners
   - Typical configuration includes:
          Web server
          Application server/middleware/CGI scripts
          Database server (hosting DBM)
   - Advantages of using Web for database access:
          Ease of use of browser software
          Web interface requires few or no changes to database
          Inexpensive to add Web interface to system



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