DROP TABLE IF EXISTS test.arraytest; CREATE TABLE test.arraytest ( created_date Date DEFAULT toDate(created_at), created_at DateTime DEFAULT now(), strings Array(String) DEFAULT emptyArrayString()) ENGINE = MergeTree(created_date, cityHash64(created_at), (created_date, cityHash64(created_at)), 8192); INSERT INTO test.arraytest (created_at, strings) VALUES (now(), ['aaaaa', 'bbbbb', 'ccccc']); INSERT INTO test.arraytest (created_at, strings) VALUES (now(), ['aaaaa', 'bbbbb', null]); -- { clientError 321 } SELECT strings from test.arraytest; DROP TABLE IF EXISTS test.arraytest;