drop table if exists aliases_test; create table aliases_test (date default today(), id default rand(), array default [0, 1, 2]) engine=MergeTree(date, id, 1); insert into aliases_test (id) values (0); select array from aliases_test; alter table aliases_test modify column array alias [0, 1, 2]; select array from aliases_test; alter table aliases_test modify column array default [0, 1, 2]; select array from aliases_test; alter table aliases_test add column struct.key Array(UInt8) default [0, 1, 2], add column struct.value Array(UInt8) default array; select struct.key, struct.value from aliases_test; alter table aliases_test modify column struct.value alias array; select struct.key, struct.value from aliases_test; select struct.key, struct.value from aliases_test array join struct; select struct.key, struct.value from aliases_test array join struct as struct; select class.key, class.value from aliases_test array join struct as class; drop table aliases_test;