Set Operations & Duplicate Tuples
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- Formal query languages are based on mathematical relations.
- Thus no duplicates appear in relations.
- As duplicate removal is expensive, SQL allows duplicates.
- To remove duplicates, we use the distinct keyword.
- To ensure that duplicates are not removed, we use the all keyword.
Page created and maintained by Osmar R. Zaï ane
Last Update:
Mon Oct 16 16:41:58 PDT 1995