Re: "log file parallel write" wait times get increased a lot after upgrading from 10203 to 10204

On Tue, Nov 30, 2010 at 10:50 PM, <Joel.Patterson_at_crowley.com> wrote:

> Clearer, would be ‘…so did you change it in 10203’?
>
>
>
> Joel Patterson
> Database Administrator
> 904 727-2546
> ------------------------------
>
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Joel.Patterson_at_crowley.com
> *Sent:* Tuesday, November 30, 2010 9:35 AM
> *To:* eagle.f_at_gmail.com; oracle-l_at_freelists.org
> *Subject:* RE: "log file parallel write" wait times get increased a lot
> after upgrading from 10203 to 10204
>
>
>
> The default for _*lgwr_async*_io = false, right? At least it is in my
> database.
>
>
>
> It is a hidden parameter, so was it changed in 10203? Perhaps … Not sure
> how much documentation there is on these parameters, but might be inclined
> to believe that because they are hidden there is a shortage of
> documentation.
>
>
>
>
>
>
>
> Joel Patterson
> Database Administrator
> 904 727-2546
> ------------------------------
>
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Eagle Fan
> *Sent:* Tuesday, November 30, 2010 2:07 AM
> *To:* oracle-l_at_freelists.org
> *Subject:* "log file parallel write" wait times get increased a lot after
> upgrading from 10203 to 10204
>
>
>
> hi:
>
> I noticed that after upgraded from 10203 to 10204, the number of waits of
> parallel write got increased a lot.
>
> We are using lgwr async IO (_lgwr_async_io=true and disk_asynch_io=true).
> OS is Solaris 10.
>
> SNAP_TIME TOTAL_WAITS TIME_WAITED
>
> ----------------- ----------- -----------
>
> 20100425 00:00:00 1193 20
>
> 20100426 00:00:00 1187 19
>
> 20100427 00:00:00 83753743 3122627 -- after upgraded from 10203 to
> 10204
>
> 20100428 00:00:00 94783396 3353594
>
> 20100429 00:00:00 96792543 3320591
>
> 20100430 00:00:00 98197875 3245199
>
> 20100501 00:00:00 98144618 3162137
>
>
> I checked several databases, all of them had the same behavior.
>
> I tried to find some docs to explain this on metalink, but I didn't find
> anything.
>
> Did anybody also have such change before? What's the reason behind this?
>
> And I'm curious what the result is if _lgwr_async_io is false.
>
> Thanks in advance.
>
> --
> Eagle Fan (www.dbafan.com)
>

-- 
Eagle Fan (www.dbafan.com)

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