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SQLIntermediate#indexes#performance
SQLIntermediate#sets
What are INTERSECT and EXCEPT/MINUS?
INTERSECT returns rows present in both queries; EXCEPT (MINUS in Oracle) returns rows in the first query that are not in the second. Both remove duplicates.
Example
SELECT id FROM active_users INTERSECT SELECT id FROM paying_users; SELECT id FROM all_users EXCEPT SELECT id FROM banned_users;