Tente isto:
SELECT T1.idA, T1.infos
FROM XXX T1
JOIN
(
SELECT idA
FROM XXX
GROUP BY idA
HAVING COUNT(*) >= 2
) T2
ON T1.idA = T2.idA
O resultado para os dados que você postou:
idaA infos 201 1899 201 1959
SELECT T1.idA, T1.infos
FROM XXX T1
JOIN
(
SELECT idA
FROM XXX
GROUP BY idA
HAVING COUNT(*) >= 2
) T2
ON T1.idA = T2.idA
idaA infos 201 1899 201 1959
