MANAGING DATA AND INFORMATION

• Bit


  Binary digIT, the basic unit of digital data consisting of 0 or 1
• Byte


  8 bits, the basic measure of storage in computers
• 8 bits in a byte is 256 different codes (00000000-11111111)
• ASCII Code


  Assigns a unique character to each pattern of 0s and 1s in a byte
• Data Hierarchy


  • Bit
  • Byte
  • Field
  • Record
  • File
  • Database
• Entity


  A person, place, thing, or event about which information is maintained
• Attribute


  Each characteristic or quality describing a particular entity
• Primary Key


  The field that uniquely identifies the record
• Secondary Key


  Field does not identify the records uniquely, but can be used to form logical groups of records
• Sequential media (tape)


  • Stores records sequentially based on key values
• Direct (or random) media (disks)


  • Use other techniques like Indexed Sequential Access Method (ISAM) and Direct File Access Method
• Index


  Lists the key field of each record and where that record is physically located
• Transform algorithm


  Translates the key field value directly into the record's storage location
• Traditional File Environment


  • The organization has multiple applications with related data files
• Problems with Traditional File Environment

  • Data redundancy
  • Data inconsistency
  • Data isolation
  • Security
  • Data integrity
  • Application/data dependence
• Database Management System (DBMS)

  Provides access to the data
• Choices for locating data in databases

  • Centralized
  • Distributed (Replicated or Partitioned)
• Database Development


  1. Develop Conceptual design

  2. Organize with Entity-Relationship (ER) modelling

  3. Analyse the data structure by applying Normalization

  4. Physically implement the data structure in the DBMS software
• Entity-Relationship (ER) Model


  Process of planning the database design including Entity classes, Instances, Identifiers, and Relationships
• Normalization


  Method that reduces a relational database to its most streamlined form to achieve minimum redundancy, maximum data integrity, and best processing performance
• Data Warehouse


  A database system designed to support management decision-making, with emphasis on organising data in convenient, meaningful ways
• Data Mart


  Small scale, simpler data warehouse, easier to implement
• Data Mining


  Extracting new insights from data warehouse using sophisticated tools and algorithms to discover hidden patterns, correlations, and relationships
• Data Mining Techniques


  • Classifying
  • Clustering
  • Associating
  • Sequencing
  • Forecasting
• Microsoft Office Access


  A database management system (DBMS) that allows creating, adding, changing, deleting, sorting, retrieving, and reporting on data in a database
• Features of Microsoft Office Access

  • Data entry and update
  • Queries
  • Forms
  • Reports
  • Web Support