Re: Chained vs. migrated rows - Any easy way to tell the
Date: Thu, 6 Nov 2008 10:38:30 +0000
dbms_stats also sets both empty_blocks and avg_space to 0
If both are also 0 then, you know that chain_cnt is 0 because it hasn't been
, or because there aren't any chained or migrated rows.
On 06/11/2008, Christian Antognini <Christian.Antognini_at_trivadis.com> wrote:
> 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
> 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.
> Chris Antognini
> Troubleshooting Oracle Performance, Apress 2008
-- regards _________________________ David Kurtz Go-Faster Consultancy Ltd. tel: +44 (0)7771 760660 fax: +44 (0)7092 348865 mailto:david.kurtz_at_go-faster.co.uk web: www.go-faster.co.uk Book: PeopleSoft for the Oracle DBA: http://www.psftdba.com The PeopleSoft DBA Blog: http://psftdba.blogspot.com PeopleSoft DBA Forum: http://groups.yahoo.com/group/psftdba -- http://www.freelists.org/webpage/oracle-lReceived on Thu Nov 06 2008 - 04:38:30 CST