put a flag on it so you get an email when it's available :)
- Darrell Landrum <DLANDRUM_at_zalecorp.com> wrote:
> I'm ready for Jonathon's next book.
> Along those lines, I think Amazon is going to start charging me for
> frequent searches to see if your book is available for pre-order yet.
>
> >>> cary.millsap_at_hotsos.com 05/08/03 11:52AM >>>
> High BCHR is not *necessarily* bad, as Zhu Chao says. But, a
> systemwide
> BCHR
> in excess of 95% or so is often an indication of one or more
> inefficiencies
> that can result in greatly improved performance if corrected:
>
> - SQL that motivates excessive numbers of unnecessary LIO calls
> (consistent
> gets, db block gets, buffer is pinned count, buffer is not pinned
> count,
> etc. [Thanks, Jonathan Lewis for teaching me about the "pinned"
> statistics.])
> - Applications that fetch one row at a time instead of using array
> fetch
> technology [thanks again to Jonathan for bringing this to my
> attention
> too].
> - Applications that roll back more often than they should [Jonathan
> again].
>
> For more information, see my "Why a 99% buffer cache hit ratio is
> *not*
> ok",
> and perhaps Jonathan will tell you how to access his "The database
> gets
> better but the metrics look worse" article that he presented at IOUG.
>
>
> Cary Millsap
> Hotsos Enterprises, Ltd.
> http://www.hotsos.com
>
> Upcoming events:
> - Hotsos Clinic 101 in London, Reykjavik, Ottawa, Dallas, Washington,
> Denver, Sydney
> - Visit www.hotsos.com for schedule details...
>
>
> -----Original Message-----
> Sent: Thursday, May 08, 2003 3:32 AM
> To: Multiple recipients of list ORACLE-L
>
> Hi,stephane,
> Though BCHR tuning method is widely critiqued, high buffer cache
> hit
> ratio is not necessary bad either, right?
> Maybe high cache hit ration and v$bh with a lot of free/cr block
> means
> too big data buffer.
> Here is an example of too big data buffer:
>
>
> 15:29:44 SQL> select /*+rule*/ status,count(*) from v$bh group by
> status;
>
> STATU COUNT(*)
> ----- ----------
> cr 55120
> free 54656
> scur 17696
> xcur 24549
>
> 4 rows selected.
>
> Elapsed: 00:00:01.32
> While in another database with large sga,I think this buffer
> cache
> is
> not too big:
>
> 15:27:05 perfstat_at_BIDDB.EACHNET.COM> select /*+rule*/ status,count(*)
> from
> v$bh group by status;
>
> STAT COUNT(*)
>
> ---- ----------
>
> cr 11162
>
> read 1
>
> xcur 1037413
>
>
> Regards
> zhu chao
> msn:chao_ping_at_163.com
> www.cnoug.org(China Oracle User Group)
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> Sent: Monday, May 05, 2003 7:11 PM
>
>
> > High BCHR, V$BH ...
> >
> > >----- ------- Original Message ------- -----
> > >From: Arvind Kumar <arvindk_at_sqlstarintl.com>
> > >To: Multiple recipients of list ORACLE-L
> > ><ORACLE-L_at_fatcity.com>
> > >Sent: Mon, 05 May 2003 02:41:36
> > >
> > >Dear All,
> > >
> > > how can i check if my buffer cache is bigger
> > >than necessary ?oracle db
> > >version is 8.1.7.
> > >
> > >
> > >Thanks
> > >
> > >
> > >Arvind
> > >
> > >
> > >--
> > >Please see the official ORACLE-L FAQ:
> > >http://www.orafaq.net
> > >--
> > >Author: Arvind Kumar
> > > INET: arvindk_at_sqlstarintl.com
> > >
> > >Fat City Network Services -- 858-538-5051
> > >http://www.fatcity.com
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> > >(or the name of mailing list you want to be removed
> > >from). You may
> > >also send the HELP command for other information
> > >(like subscribing).
> > >---------------------------------------------------
> > >------------------
> >
> > Regards,
> >
> > Stephane Faroult
> > Oriole
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: Stephane Faroult
> > INET: sfaroult_at_oriolecorp.com
> >
> > Fat City Network Services -- 858-538-5051 http://www.fatcity.com
>
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> services
> >
> ---------------------------------------------------------------------
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB ORACLE-L
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> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: zhu chao
> INET: chao_ping_at_vip.163.com
>
> Fat City Network Services -- 858-538-5051 http://www.fatcity.com
> San Diego, California -- Mailing list and web hosting services
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> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Cary Millsap
> INET: cary.millsap_at_hotsos.com
>
> Fat City Network Services -- 858-538-5051 http://www.fatcity.com
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> --
>
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Received on Thu May 08 2003 - 13:47:45 CDT
