Re: Surprising Performance Changes with Oracle 11.2.0.1 (Long Post)
From: Gerard H. Pille <ghpille_at_hotmail.com>
Date: Wed, 9 Sep 2009 02:48:45 -0700 (PDT)
Message-ID: <090a6e0f-6f7b-4d74-997b-088f9ea12e61_at_k39g2000yqe.googlegroups.com>
Hallo Charles,
Date: Wed, 9 Sep 2009 02:48:45 -0700 (PDT)
Message-ID: <090a6e0f-6f7b-4d74-997b-088f9ea12e61_at_k39g2000yqe.googlegroups.com>
Hallo Charles,
I'd like to see your statistics for this select:
SELECT /*+ index (t1 ind_t1) */
ID,
DESCRIPTION
FROM
sys.T1 t1
WHERE
ID >= 9991
/
I suppose you were aware of the skew in the index, but how does this account for the difference in performance?
On my old PC - with a new disk - the FTS takes 2 minutes, the IS 20 minutes, selecting id between 1 and 400 via index takes over 3 hours.
Kind regards,
Gerard Received on Wed Sep 09 2009 - 04:48:45 CDT