RE: Chained vs. migrated rows - Any easy way to tell the
From: Christian Antognini <Christian.Antognini_at_trivadis.com>
Date: Thu, 6 Nov 2008 10:35:33 +0100
Message-ID: <F2C9CCA71510B442AF71446CAE8AEBAF0136230E@MSXVS04.trivadis.com>
Date: Thu, 6 Nov 2008 10:35:33 +0100
Message-ID: <F2C9CCA71510B442AF71446CAE8AEBAF0136230E@MSXVS04.trivadis.com>
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 ANALYZE was never used to compute statistics for it.
If 2, at some time in the past the statistics were compute with ANALYZE. Since DBMS_STATS doesn't compute it, you see the value at the time of the last execution of ANALYZE.
HTH
Chris Antognini
Troubleshooting Oracle Performance, Apress 2008 http://top.antognini.ch
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Nov 06 2008 - 03:35:33 CST