Rapid Application Development / Advanced Excel Development

Database (Relational)

• Useful for flexible and efficient storage and updating
• Identify Entities (nouns), Attributes (adjectives) and relationships (verbs) in problem statement
• 2 approaches
  • Top down (identify entities then attributes)
  • Bottom up (group attributes to describe entities)
• Data normalisation
  • Basically keep related items together
  • Provides design flexibility
  • 3rd Normal Form (TNF/3NF)
  • All items depend on the key (a unique identifier), the whole key and nothing but the key.
• More useful at the transaction processing end rather than analysis and reporting. (eg sales recording)
• Analysis performance can be poor (often requires many joins)