drop table if exists tab; create table tab (x LowCardinality(String)) engine = MergeTree order by tuple(); insert into tab values ('a'), ('bb'), ('a'), ('cc'); select count() as c, x in ('a', 'bb') as g from tab group by g order by c; drop table if exists tab; -- https://github.com/ClickHouse/ClickHouse/issues/44503 CREATE TABLE test(key Int32) ENGINE = MergeTree ORDER BY (key); insert into test select intDiv(number,100) from numbers(10000000); SELECT COUNT() FROM test WHERE key <= 100000 AND (NOT (toLowCardinality('') IN (SELECT '')));