Re: Optimizer not using index on 120M row table

On Wed, Apr 30, 2003 at 12:56:11AM -0500, Jim C. Nasby wrote:
> On Wed, Apr 30, 2003 at 12:14:34AM -0400, Tom Lane wrote:
> > Plenty, see many past threads in pgsql-performance and other lists.
> > There are strong reasons to think that you should let the kernel do the
> > bulk of the caching work.
>
> OK, anyone have any ideas on how to get FreeBSD to cache more than 300M?
> :)

Ok, looks like I was just mis-reading top/not understanding the FBSD vm
subsystem well enough.

I'll try and dig up stuff in the archives about shared_buffer settings,
but it seems like it would be really useful to have a whitepaper
describing why the OS should be left to do caching, what pgsql actually
tries to use it's shared buffers for (beyond simple read caching), and
how best to size shared_buffers.
--
Jim C. Nasby (aka Decibel!) jim(at)nasby(dot)net
Member: Triangle Fraternity, Sports Car Club of America
Give your computer some brain candy! www.distributed.net Team #1828

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