RE: Chained vs. migrated rows - Any easy way to tell the

  • From: <Joel.Patterson@xxxxxxxxxxx>
  • To: <martin.a.berger@xxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 18 Nov 2008 08:32:01 -0500

Ah... Thanks.  I should just leave the dba_tables.chain_cnt alone?   I
could clean it up dba_tables I suppose?

Not sure about Martins comment concerning object_space_usage.

Joel Patterson
Database Administrator
904  727-2546

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Martin Berger
Sent: Tuesday, November 18, 2008 7:44 AM
Subject: Re: Chained vs. migrated rows - Any easy way to tell the

would it be save to run
DBMS_SPACE.OBJECT_SPACE_USAGE to check for chain_pcent  > 0 without  
disturbing DBMS_STATS at all?

just a guess - never tried yet.
And I also doesn't see a valid answer for the question between chained  
and migrated rows there.


Martin Berger

Am 06.11.2008 um 10:35 schrieb Christian Antognini:

> Hi Joel
>> The difference between dba_tables.chain_cnt and what is contained
>> in chained_rows table now is still a mystery.  Stats are collected
>> nightly.
> DBMS_STATS doesn't compute the value chain_cnt. Therefore, there are  
> two
> possibilities:
> 1) dba_tables.chain_cnt = 0
> 2) dba_tables.chain_cnt > 0
> If 1, either the table doesn't contain chained/migrated rows or  
> was never used to compute statistics for it.
> If 2, at some time in the past the statistics were compute with  
> Since DBMS_STATS doesn't compute it, you see the value at the time of
> the last execution of ANALYZE.


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