select * from db1.table1 t1
full outer join db2.table2 t2 on t1.id = t2.id
where t1.id <> t2.id
or t1.col2 <> t2.col2 or ...
select * from db1.table1 t1
full outer join db2.table2 t2 on t1.id = t2.id
where t1.id <> t2.id
or t1.col2 <> t2.col2 or ...