DROP TABLE IF EXISTS table_a; DROP TABLE IF EXISTS table_b; CREATE TABLE table_a ( event_id UInt64, something String, other Nullable(String) ) ENGINE = MergeTree ORDER BY (event_id); CREATE TABLE table_b ( event_id UInt64, something Nullable(String), other String ) ENGINE = MergeTree ORDER BY (event_id); INSERT INTO table_a VALUES (1, 'foo', 'foo'), (2, 'foo', 'foo'), (3, 'bar', 'bar'); INSERT INTO table_b VALUES (1, 'bar', 'bar'), (2, 'bar', 'bar'), (3, 'test', 'test'), (4, NULL, ''); SELECT s1.other, s2.other, count_a, count_b, toTypeName(s1.other), toTypeName(s2.other) FROM ( SELECT other, count() AS count_a FROM table_a GROUP BY other ) s1 ALL FULL JOIN ( SELECT other, count() AS count_b FROM table_b GROUP BY other ) s2 ON s1.other = s2.other ORDER BY s2.other DESC, count_a; SELECT s1.other, s2.other, count_a, count_b, toTypeName(s1.other), toTypeName(s2.other) FROM ( SELECT other, count() AS count_a FROM table_a GROUP BY other ) s1 ALL FULL JOIN ( SELECT other, count() AS count_b FROM table_b GROUP BY other ) s2 USING other ORDER BY s2.other DESC, count_a; SELECT s1.something, s2.something, count_a, count_b, toTypeName(s1.something), toTypeName(s2.something) FROM ( SELECT something, count() AS count_a FROM table_a GROUP BY something ) s1 ALL FULL JOIN ( SELECT something, count() AS count_b FROM table_b GROUP BY something ) s2 ON s1.something = s2.something ORDER BY count_a DESC; SELECT s1.something, s2.something, count_a, count_b, toTypeName(s1.something), toTypeName(s2.something) FROM ( SELECT something, count() AS count_a FROM table_a GROUP BY something ) s1 ALL RIGHT JOIN ( SELECT something, count() AS count_b FROM table_b GROUP BY something ) s2 USING (something) ORDER BY count_a DESC; SET joined_subquery_requires_alias = 0; SELECT something, count_a, count_b, toTypeName(something) FROM ( SELECT something, count() AS count_a FROM table_a GROUP BY something ) ALL FULL JOIN ( SELECT something, count() AS count_b FROM table_b GROUP BY something ) USING (something) ORDER BY count_a DESC; DROP TABLE table_a; DROP TABLE table_b;