NVL and DECODE are all old methods.

Another method is using COALESCE function.

SELECT
t.Start_Dat,
t.End_Dat
FROM
Tariff t
WHERE
t.Start_Dat >=
COALESCE((SELECT
max(t.start_dat)
FROM Tariff t
WHERE t.Start_dat <=
to_date('19/11/2003', 'dd/mm/yyyy'),
to_date('10/11/2003', 'dd/mm/yyyy')
);

Tamil