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Use ranges

Sometimes it can be handy to work with ranges. 		Introduction 1. Scope 2. Logical Design
3. Technical Optimisation
Goal Optimisation steps
Use ranges
Denormalise Combine tables Store derived data Add indexes Sort 4. Implementation End
Postcode Street City
2803 DA Groenhovenweg Gouda
2803 DB Groenhovenweg Gouda
2803 DC Groenhovenweg Gouda
... ... ...
2803 DL Groenhovenweg Gouda
This could be solved with a range.
Start Postcode End Postcode Street City
2803 DA 2803 DL Groenhovenweg Gouda
Be careful: Ranges make the software more complex. Adding an extra postcode can be quite a puzzle:
  • Do nothing, the postcode is in an existing range?
  • Create a new range?
  • Decrease the start postcode of an existing range?
  • Increase the end postcode of an existing range?
  • Split an existing range and insert a new one?
Next: Denormalise