RE: autotrace issue
- From: "Christian Antognini" <Christian.Antognini@xxxxxxxxxxxx>
- To: <madan.sanjay@xxxxxxxxx>
- Date: Fri, 14 Oct 2005 13:34:14 +0200
Sanjay
>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.
Which is the distribution of data in field1? Do you have a histogram on it?
>It seems to be happening randomly. For most values it shows an index range
>scan.
>For others (fewer) it shows a full table scan.
It's probably because data is not evenly distributed (I don't speak of the
distribution at partition level... but the data in field1). If the following
queries return very different values it could be good that the CBO generates
different plans:
select count(*) from ... where field1 = 123456
select count(*) from ... where field1 = 1234561
HTH
Chris
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