Re: db_writer_processes tuning
From: Riyaj Shamsudeen <riyaj.shamsudeen_at_gmail.com>
Date: Mon, 9 Feb 2009 10:12:53 -0600
Message-ID: <203315c10902090812p3da67227rad567fba350af1cd_at_mail.gmail.com>
Tim
>>There is an X$ table that summarizes activity to the different DBWn
processes, but the name of it has slipped into the past and I can't recall it.
Date: Mon, 9 Feb 2009 10:12:53 -0600
Message-ID: <203315c10902090812p3da67227rad567fba350af1cd_at_mail.gmail.com>
Tim
>>There is an X$ table that summarizes activity to the different DBWn
processes, but the name of it has slipped into the past and I can't recall it.
Are you referring to x$kcbwds?
1 select dbwr_num, sum(BUF_GOT),sum(SUM_WRT), sum(PREAD),sum(PWRITE) from
x$kcbwds
2* group by dbwr_num
SQL> /
DBWR_NUM SUM(BUF_GOT) SUM(SUM_WRT) SUM(PREAD) SUM(PWRITE)
---------- ------------ ------------ ---------- -----------
0 244517606 12940957 192045117 12940957 1 244449224 12926116 192040603 12926116 2 244416438 12930180 192024063 12930180 3 244375475 12933143 192025129 12933143 4 244345225 12925632 192029519 12925632 5 244270375 12915465 192024015 12915465 6 244268520 12927650 192025821 12927650
7 rows selected.
-- Cheers Riyaj Shamsudeen Principal DBA, Ora!nternals - http://www.orainternals.com Specialists in Performance, Recovery and EBS11i Blog: http://orainternals.wordpress.com On Mon, Feb 9, 2009 at 10:03 AM, Guillermo Alan Bort <cicciuxdba_at_gmail.com>wrote:Received on Mon Feb 09 2009 - 10:12:53 CST
> mine does... that is:
> two thousand eight hundred and seventy five dollars rounds up to four
> dollars ^_^
>
> hth
> Alan Bort
> Oracle Certified Professional
>
>
>
> On Mon, Feb 9, 2009 at 1:59 PM, Milen Kulev <makulev_at_gmx.net> wrote:
> > Hello Nigel,
> > it is definitely rounding error (2,875 -> 4 ;) ).
> > It is really pitty that my emplyer dowsn't round up my salary int this
> way
> > ;)
> >
> > Anyway, the databases are running pretty well even with 4 DB writer
> > processes.
> >
> > Best Regards. Milen
> >
> >
> > Nigel Thomas wrote:
> >
> > Small thing:
> >
> > (16 + 7)/8 = 3, not 4
> >
> > WTF?
> >
> > 2009/2/9 Milen Kulev <makulev_at_gmx.net>
> >>
> >> Hello Vladimir,
> >> as fas as know, according to Oracle the optimal count of DB writer
> >> processes is
> >> "(CPU_COUNT+7)/8". For 16 CPUs that would give you 4 DB Writer
> processes.
> >> I have used this setting (also with VxFS), and there were no problems.
> >>
> >> HTH. MILEN
> >>
> >
> >
> >
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
-- http://www.freelists.org/webpage/oracle-l