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Performance Tuning (cont)

Tuning requires us to consider the following:
  • which queries and transactions will be used?
      (e.g. check balance for payment, display recent transaction history)
  • how frequently does each query/transaction occur?
      (e.g. 90% withdrawals; 10% deposits; 50% balance check)
  • are there time constraints on queries/transactions?
      (e.g. EFTPOS payments must be approved within 7 seconds)
  • are there uniqueness constraints on any attributes?
      (define indexes on attributes to speed up insertion uniqueness check)
  • how frequently do updates occur?
      (indexes slow down updates, because must update table and index)