4 CREATE TABLE t_subcolumns (a Array(UInt64), s Nullable(String), m Map(String, UInt64)) ENGINE = MergeTree ORDER BY tuple() INSERT INTO t_subcolumns SELECT range(number % 20), toString(number), mapFromArrays(range(number % 20), range(number % 20)) FROM numbers_mt(50000000) OPTIMIZE TABLE t_subcolumns FINAL SELECT count() FROM t_subcolumns WHERE NOT ignore(length(a)) SELECT count() FROM t_subcolumns WHERE notEmpty(a) SELECT count() FROM t_subcolumns WHERE NOT ignore(length(m)) SELECT count() FROM t_subcolumns WHERE notEmpty(m) SELECT count() FROM t_subcolumns WHERE isNotNull(s) SELECT count(s) FROM t_subcolumns DROP TABLE t_subcolumns