3.1.02. Value in design

  • Allocated arbitrarily by DBD under ER/EER
  • Goodness at
    • Internal/storage level (base relations only)
      • Reducing nulls - obvious storage benefits /frequent
      • Reducing redundancy - for efficient storage/anomalies
    • Conceptual level
      • Semantics of the attributes /single entity:relation
      • No spurious tuple generation /no match Attr,-PK/FK