ORDER BY - using index

From: <boguslaw.pazur_at_marcos-bis.com.pl>
Date: 7 Mar 2006 01:41:07 -0800
Message-ID: <1141724467.219506.183180@j52g2000cwj.googlegroups.com>

Hello.

I have simply select with ORDER BY like
SELECT x FROM y ORDER BY z
Oracle (version 10.2) does not use index despite of there is index on column z. There are many records in table so SELECT takes long. Of course I can use hint to point index.
1. Is it possible to set Oracle parameters to choose adequate index automatically (without hint) in this kind of SELECT statements? 2. Why Oracle does not use index in this situation? (Time difference is like 1 : 60).

TIA Boguslaw Pazur Received on Tue Mar 07 2006 - 03:41:07 CST