Please enable JavaScript.

Coggle requires JavaScript to display documents.

Data (DATABASE (FLAT DATABASE or Table (RELATIONAL DATABASES (DATABASE…

- - - - Data types
        Text
        Number
        Date
        Currency
        Logical
    - - Two or more tables
      - normalisation
      - ENTITY
        Tangible or Intangible
        e.g. Student
        
        Attributes
        of an entity
        e.g. Name, DOB etc
      - Joining Table
        connects Entities
      - Creates a
        MANY-TO-MANY-RELATIONSHIP
      - Permit different VIEWS of the data
        produces a new virtual table which can also be queried
        
        Allow data from multiple tables to be scrutinised alongside
        
        Data on demand
        
        Security e.g. read only
      - DATABASE MANAGEMENT SYSTEMS
        (DBMS's)
        
        Microsoft Access
        
        Oracle
        
        Microsoft SQL Server
        
        MySQL
        
        Legacy Systems
        age due to different interpretations of SQL
        
        BIG DATA
        
        In 2013 estimated humanity had created 5 exabytes of data
        5 x 10^18 bytes or 5 billion gigabytes
        
        By 2015 we were generating this every 2 days
        
        Sampling - Limited in value and subject to unintended bias
        
        Credit Card fraud detection uses big data
        
        Xoom
        
        The Three 'V's'
        
        Volume
        
        Velocity
        
        Variety
        
        Veracity
        
        DATA VOLUME VERSUS DATA QUALITY
        
        CLUSTER COMPUTING
        
        Nodes
        
        Master computer
        
        Hard Disks for storage
        
        Nodes relatively cheap
        
        More can be added or replaced
        
        resilient to failure
        
        GRID COMPUTERS
        
        Different types of computer
        
        Do not need to be on the same network
        
        The 'Toos'
        
        too much data
        
        too complex
        
        too many (updates)