Re: New IBM Nonsense

From: Serge Rielau <srielau_at_ca.ibm.com>
Date: Sat, 22 Jan 2005 13:10:23 -0500
Message-ID: <35fj7cF4ki6acU1@individual.net>

Jonathan Lewis wrote:
> Note in-line
>
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> The Co-operative Oracle Users' FAQ
>
> http://www.jlcomp.demon.co.uk/seminar.html
> Public Appearances - schedule updated Jan 22nd 2005
>
>
>
>
> "Serge Rielau" <srielau_at_ca.ibm.com> wrote in message
> news:35fc2gF4dmo62U1_at_individual.net...
>

>>PS: Anyone know why RAC logs so much?
>>

>
>
> If you can describe a simple scenario where the
> logging done on RAC signficantly exceeds the
> logging done on a non-RAC installation - with
> an indication of data change volume, cross-instance
> calls, and quantities of log generated, I can probably
> tell you what's causing the difference. (And version
> of Oracle, of course).
>
>
>

>>-- 
>>Serge Rielau
>>DB2 SQL Compiler Development
>>IBM Toronto Lab

>
>
>

I'm looking at the 1M+ TpmC Linux RAC result using O10g vs the 1M TpmC Result without RAC on HP - also O10g
http://www.tpc.org/results/FDR/TPCC/HP%20Integrity%20rx5670%20Cluster%2064P_FDR.pdf vs.
http://www.tpc.org/results/FDR/TPCC/hp_tpcc_sd_1mil_fdr.pdf

Apparently the Linux RAC required 24500 GB (24.5TB!) for 8 hours of logging. The HP SMP result only 2,481.03 (2.5TB). That's a factor of 10.

Now, if my understanding of RAC is correctly logging goes up for hot pages. So I could imagine that the counter for the ORDERID may be nasty, but not that nasty. Also only 10% of the orders are remote and the cluster is partitioned.

Cheers
Serge

-- 
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab

Received on Sat Jan 22 2005 - 12:10:23 CST