Aggregation & Duplicate Removal (cont.)

• Nested Loops

  • Easiest of the three
  • Does not work well for large inputs

• Sorting

  • Sort for common elements which results in simple aggregation/duplicate removal
  • Should remove duplicates as early as possible

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Cost analysis:

Nested loops- no cost evaluation is given.

Sorting- decided by the number of merge levels & the effect of early duplicate removal on each merge step.