Postgres Seleccione columnas duplicadas
select Column1, Column2, count(*)
from yourTable
group by Column1, Column2
HAVING count(*) > 1
riffrazor
select Column1, Column2, count(*)
from yourTable
group by Column1, Column2
HAVING count(*) > 1select * from yourTable ou
where (select count(*) from yourTable inr
where inr.sid = ou.sid) > 1