Edgar,

have you tried to use a GROUP BY clause in your subselect instead of DISTINCT? Sometimes this seems to be faster - just a feeling, no scientific experiance.

SELECT *                 ;
    FROM view1           ;
    WHERE Acc_field IN   ;
        (SELECT Acc_field                                ;
             FROM view1                                  ;
             WHERE year = '2001' AND Acc_field LIKE '5%' ;
             GROUP BY Acc_field)

Robert