How to tune up this simple query
From: Ed Wong <ewong_at_mail.com>
Date: 28 Jan 2002 13:29:45 -0800
Message-ID: <a5ae1554.0201281329.32fd82b0_at_posting.google.com>
[Quoted] [Quoted] I have this table named testresult with 10 million records: id number(10) --pk, indexed
testid number(10) --fk reference to test.id, indexed result varchar2(100)
Date: 28 Jan 2002 13:29:45 -0800
Message-ID: <a5ae1554.0201281329.32fd82b0_at_posting.google.com>
[Quoted] [Quoted] I have this table named testresult with 10 million records: id number(10) --pk, indexed
testid number(10) --fk reference to test.id, indexed result varchar2(100)
The following query takes 20 seconds:
select min(id) from testresult where testid > 100000;
I have a program that does this query in a loop(because testid keep changing). So 20 seconds is not acceptable.
How to tune this up? How come it doesn't use index of testid? The explain plan shows it's doing a full table scan instead of using index of testid.
Thanks,
ewong
Received on Mon Jan 28 2002 - 22:29:45 CET