CREATE TABLE record (swimmer_id VARCHAR2)
CREATE TABLE swimmer (name VARCHAR2, id VARCHAR2)

Find the name of the swimmer who has at least 2 records.
SELECT t1.name FROM swimmer AS t1 JOIN record AS t2 ON t1.id = t2.swimmer_id GROUP BY t2.swimmer_id HAVING COUNT(*) >= 2
SELECT "t1"."name" FROM "swimmer" "t1" JOIN "record" "t2" ON "t1"."id" = "t2"."swimmer_id" GROUP BY "t2"."swimmer_id" HAVING COUNT(*) >= 2