SELECT *
FROM (SELECT FECHA_MUESTRA DIA,
LABEL,
DL_OUT_TH_KBPS,
ROUND ( (DL_OUT_TH_KBPS + UL_INC_TH_KBPS) / (1000 * 1000), 2)
TOTAL_DL_UL_GBPS,
ROW_NUMBER ()
OVER (
ORDER BY
ROUND (
(DL_OUT_TH_KBPS + UL_INC_TH_KBPS) / (1000 * 1000),
2) DESC)
AS rn
FROM W4G.V_GF_DATA_GW_TH_KBPS
WHERE TRUNC (FECHA_MUESTRA) >=
TO_DATE ('01-04-2019', 'DD-MM-YYYY HH24:MI:SS')
AND TRUNC (FECHA_MUESTRA) <= TRUNC (SYSDATE - 1)
) q1
WHERE rn = 1