Thank you for the reply,

But, here it is another one:

"select
pty.party_id, bill.due_date, bill.service_tax

from
tbl_party pty join tbl_bill bill on (bill.account_id = pty.account_id) and bill.service_id = 1

where
not exists (select * from tbl_invalid inv where inv.party_id = pty.party_id)"

All of the fields you see here except "bill.due_date" and
"bill.service_tax" are indexed fields.

This query without the WHERE clause executes fast (1400 ms). When
I put the WHERE clause it goes to something like 15 minutes :((

Moreover, in the performance monitor I see only UNINDEXED reads.

Frankly I don't know what is happening!


--
Best regards,
Alexander mailto:saho@...