Re: Multiple buffer cache?

2010/2/6 Bret S. Lambert <bret(dot)lambert(at)gmail(dot)com>:
> On Fri, Feb 05, 2010 at 11:41:13PM +0200, Alexei Vladishev wrote:
>> Greetings,
>>
>> Is there a way of configuring PostgreSQL so that one specific table would
>> use, say, 4GB of buffer cache while other tables would use the rest?
>>
>> I would like to keep the table and its indexes always in "hot"
>> state, so that
>> other queries won't pollute this part of the buffer cache. It would ensure
>> reliable performance and much less disk IOPS working with the table.
>
> Fiddling with the buffer cache like that would require some sort of
> OS support, if I'm not mistaken in what you're asking for.
>
> And then, even if the support is there, you'd need to outline exactly
> how you're planning on pushing this button.
>
> Specifically, what's your usage pattern that would make this a
> win for you?
>
> If the table and its indexes can already fit into the buffer cache,
> and it's as commonly accessed as you think it is, the OS should
> probably have it cached anyway.

that's all true.

I am working on pgfincore which allow in some way to prepare buffer cache.
You need pg > 8.4 and linux (probably working with bsd too)

I don't consider it ready fo rproduction, but fine for debugging
things, if you reall care the buffer cache preload, tell me, I'll
stabilize the code in a shorter time ;)
http://villemain.org/projects/pgfincore

>
>>
>> Is it possible?
>>
>> Thanks for any hints!
>>
>> Alexei
>>
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--
Cédric Villemain