Hi,
on Windows, mainly on Win64 we have this experience:
OS are trying to do best posible file caching and putting FB cache into swap
file.
This typically starting when DB size is over ~80% of RAM.
Our final solution was simple, we was disable swap.

This solution radicaly improove system reaction time.
We don't receive any problem with memory (all machone has more then 8GB
RAM).

This mean, try to look how many RAM is used for file caching.

Slavek
Ing. Slavomir Skopalik
Jednatel spolecnosti
Elekt Labs s.r.o.
Chaloupky 158
783 72 Velky Tynec
Czech Republic
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e-mail:skopalik@...
http://www.elektlabs.cz






hmm, how 100 000 page buffer can make me run out of physical memory ? with
4ko page buffer, it's only 400 mb of memory and i have 4gb on our test
machine.

but anyway that was a good remarque (and a good guess) and it's look
logical. how to know if a program go into a memoy disk swap hell ?

thanks again ann !
stephane

--- In firebird-support@ <mailto:firebird-support%40yahoogroups.com>
yahoogroups.com, "Ann W. Harrison" <aharrison@...> wrote:

>
> svanderclock wrote:
> > no one have an idea of this behavior ?
> >> now i encountered another strange behavior, it's when i setup a big

page buffer

> >>
> >> page buffer 2048: execute time 156ms
> >> page buffer 20480: execute time 156ms
> >> page buffer 100000: execute time 15288 ms !!!
> >>
> >> any idea why when i setup a big page buffer then the execute time go

down by 100 ! the commit time don't change..

> >>
> >> many thanks by advance for your precious help !!
>
> My guess is that at 100,000 page buffers, you've run out
> of physical memory and are page faulting. Tuning a database
> is a little like cooking - the fact that a bit of salt improves
> the flavor doesn't imply that a kilo of salt will make it
> delicious.
>
> Cheers,
>
> Ann
>

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