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RE: autotrace issue

From: Yasin Baskan <>
Date: Fri, 14 Oct 2005 14:37:08 +0300
Message-ID: <083667B535F3464CA0DD0D1DAFA4E376077331DC@camexc1.kfs.local>

Isn't it normal that the plan changes with the actual value in the where clause. That is what the optimizer does. You can use a bind variable instead of that literal and see what the plan is.

[] On Behalf Of Sanjay Madan Sent: Friday, October 14, 2005 2:01 PM
Subject: autotrace issue

Hi ,

Oracle on AIX
Partitioned table ( list) ~ 10 mil rows in all distibuted almost equally across 5 partitions
field1 ( used in the query) is not the PK.

My autotrace ( traceonly explain) output for a particular query changes with the actual value of the input parameter.

select .......
where ...........
and field1 = 123456

autotrace output shows an Index range scan whereas

select .......
where ...........
and field1 = 1234561

autotrace output shows a full table scan (not the exact input values) ...

I have tried values
-both within and outside the field lengths of field1
-values actually existing in the table
-values NOT existing in the table.

It seems to be happening randomly. For most values it shows an index range scan.
For others (fewer) it shows a full table scan.

Any hints as to what could be happening or where I should look to solve the problem ?



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-- Received on Fri Oct 14 2005 - 06:39:22 CDT

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