Re: Can I tryst in "physical ... direct" figures?

From: <J.Velikanovs_at_alise.lv>
Date: Fri, 24 Sep 2004 17:06:30 +0300
Message-ID: <OF001627FD.D56F2FF9-ONC2256F19.004D651A-C2256F19.004D9BCB@alise.lv>

Thank you for ideas.
It is OLTP 200 users system.
I have found that very popular SQL use HASH operation :) The reason ir HASH not SORTs

Thank you all,
Jurijs
+371 9268222 (+2 GMT)

Thank you for teaching me.
http://otn.oracle.com/ocm/jvelikanovs.html

zhu chao <zhuchao_at_gmail.com>
24.09.2004 17:02
Please respond to zhu chao

        To:     "j.velikanovs_at_alise.lv" <j.velikanovs_at_alise.lv>
        cc:     oracle-l_at_freelists.org
        Subject:        Re: Can I tryst in "physical ... direct" figures?

Cound you use the following SQL to find out which session does most of the write?

As you mentioned you run ad-hoc query and it is like a datawarehouse, so physical reads direct can be explained via the parallel slave process doing the direct path read,

and possibly the direct path write can be done via the sqlldr direct path write? and create table as select?

maybe you can use sql like the following one to find out which session does most of the direct path write(if the session hasn't logout, or you are using middleware).
set line 200
select b.sid,a.name,b.value from v$sesstat b, v$statname a where a.statistic#=b.statistic#
and (a.name like '%physical writes direct%' or a.name like 'physical writes')
and b.value>0
order by b.value asc
/

Original Message ----- From: j.velikanovs_at_alise.lv <j.velikanovs_at_alise.lv> Date: Fri, 24 Sep 2004 16:14:53 +0300 Subject: Re: Can I tryst in "physical ... direct" figures? To: zhu chao <zhuchao_at_gmail.com>

Hi Zhu,

Thanks for respnce.
With reads it can be as you described.
At the mopment I thought more about writes. How Direct writes cant be 98% of all writes if there olmost no sorts in the system, i wonder?

Jurijs
+371 9268222 (+2 GMT)

Thank you for teaching me.
http://otn.oracle.com/ocm/jvelikanovs.html

zhu chao <zhuchao_at_gmail.com>

24.09.2004 15:36
Please respond to zhu chao

        To:        j.velikanovs_at_alise.lv 
        cc: 
        Subject:        Re: Can I tryst in "physical ... direct" figures?

Hi ,
Since disk sort is very few times, maybe it is "parallel server direct path read", since there isn't parallel_max_servers specified in your spfile, the default value is 4.
So, it is possible you are using parallel slave server to do direct path read.

-- 
Regards
Zhu Chao
www.cnoug.org





-- 
Regards
Zhu Chao
www.cnoug.org



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Received on Fri Sep 24 2004 - 09:08:37 CDT