Re: different physical access method because of disabling Automated Memory Management?
Date: Sat, 3 Jan 2009 14:25:17 -0500
I did some quick and dirty ad-hoc tests recently and thus far it seems to certainly depend on:
- _small_table_treshold as Tanel has mentioned
- Amount of table blocks already presented in the buffer cache
- Amount of dirty blocks (since we need to do an object level checkpoint for this)
(2) seems to be 1/2 of a table blocks and (3) 1/4 of a table blocks, you can see my test at http://afatkulin.blogspot.com
the main problem here is that amount of variables that Oracle could use as in input to make a decision is probably much larger than the above three I've mentioned thus it is what it is -- just documenting some observations without really approaching any reliable figures.
On Sat, Jan 3, 2009 at 3:35 AM, Martin Berger <martin.a.berger_at_gmail.com> wrote:
> Hi Tanel,
> I checked _small_table_treshold (for some reasons it was not mentioned in
> the 10053 trace.)
> You where right, there was a difference:
> _small_table_threshold => 59
> _small_table_threshold => 498
> So I adjusted my 'manual'-testcase, run it again - but still 'direct path
> Does anyone knows which subsystem takes the decision which kind of IO, and
> how to trace this?
> best regards,
> Martin Berger
-- Alex Fatkulin, http://afatkulin.blogspot.com http://www.linkedin.com/in/alexfatkulin -- http://www.freelists.org/webpage/oracle-lReceived on Sat Jan 03 2009 - 13:25:17 CST