--https://github.com/ClickHouse/ClickHouse/issues/59402 CREATE TABLE t1 ( f1 Int32, f2 Map(LowCardinality(String),LowCardinality(String)), f3 Map(String,String), f4 Map(Int32,Int32) ) ENGINE=Memory AS SELECT 1 as f1, map(number%2,number%10) as f2, f2 as f3, f2 as f4 from numbers(1000111); SET max_block_size=10; -- { echoOn } SELECT f1, f2['2'], count() FROM t1 GROUP BY 1,2 order by 1,2; SELECT f1, f3['2'], count() FROM t1 GROUP BY 1,2 order by 1,2; SELECT f1, f4[2], count() FROM t1 GROUP BY 1,2 order by 1,2;