Question : Speeding up a simple UPDATE in Oracle SQL

Hi
I am using the following ORACLE SQL Code to update one row in a database

UPDATE MARKET_VOLATILITY_SURFACE
SET  C       = 12.875,   P        = 18.775,   CB=11.5,   CA= 14.25,   PB= 18.15,   PA    = 19.4
WHERE     TRUNC(MDATE) = trunc(TO_Date( '06/06/2010 12:00:40 AM', 'MM/DD/YYYY HH:MI:SS AM'))
AND  BS=6
AND  CT = 1
AND PERIOD    = 3
AND  D    = 10;

COMMIT;

The operation takes about 3 seconds.
There are 1,450,000 rows in the databas and there is an index on MDATE, BS, CT, PERIOD and D.

Does anyone have any idea how this can be dramatically speeded up?

Thank you!

Answer : Speeding up a simple UPDATE in Oracle SQL

Try avoidig using functions on index columns: often that prevents the index being  used.
try here
WHERE MDATE between trunc(date)  and trunc(date) + 1  -- so MDATE is not used with a function