any suggestions on how to optimize the query below. it runs fine when the there are 40,000 or fewer records in table test (95% of the time). however every once in a while i get 250,000 record sets. i have tried creating indexes on all eight fields.

thanx.

SELECT DISTINCT t1.invnum, t1.vendname, t1.invdate, t1.invamt, t1.vendnum, t1.checknum, t1.checkdat, t1.misc;
FROM test t1, test t2 ;
WHERE t1.invnum != t2.invnum ;
AND t1.vendname = t2.vendname ;
AND t1.invdate !=t2.invdate ;
AND t1.invamt =t2.invamt ;
INTO TABLE report6