ClickHouse/dbms/tests/queries/0_stateless/00532_topk_generic.sql

SELECT k, topK(v) FROM (SELECT number % 10 AS k, arrayMap(x -> arrayMap(x -> x = 0 ? NULL : toString(x), range(x)), range(intDiv(number, 13))) AS v FROM system.numbers LIMIT 100) GROUP BY k ORDER BY k;