A better query needed

Question

DELETE FROM ACCOUNT_ASCTN WHERE LIST_ID = 3999 AND
ACCOUNT_ID IN (
SELECT ACCOUNT_ID FROM ACCOUNT_ASCTN WHERE
LIST_STATUS_CODE ='A'
AND LIST_ID =3999 MINUS (SELECT ACCOUNT_ID FROM WORKLIST_ACNT ));
as sometimes it takes around 40 minutes for a particular list id if there are too many records in the acount_asctn table.
I tried with exists but its only making it better by a few seconds .

Answer 1

Hi , I know NOT IN is not recommended. But there is no harm if you just checking the performance.
Any way you can use this also:
DELETE FROM ACCOUNT_ASCTN aa
WHERE LIST_ID = 3999
AND LIST_STATUS_CODE ='A'
AND acccount_id NOT EXISTS (SELECT NULL FROM WORKLIST_ACNT wa
WHERE aa.ACCOUNT_ASCTN=wa.ACCOUNT_ID );
And if WORKLIST_ACNT has a lot of records and there is an index on ACCOUNT_ID you can try this approach also.
DELETE FROM ACCOUNT_ASCTN aa
WHERE LIST_ID = 3999
AND LIST_STATUS_CODE ='A'
AND (SELECT count(wa.account_id) FROM WORKLIST_ACNT wa
WHERE aa.ACCOUNT_ASCTN=wa.ACCOUNT_ID ) = 0;
Also check is there index for LIST_ID and LIST_CODE_STATUS on ACCOUNT_ASCTN table.
Regards