On 8 Jul 2005, at 20:21, Merlin Moncure wrote:
Stuart,
I'm putting together a road map on how our systems can scale as our
load
increases. As part of this, I need to look into setting up some fast
read only mirrors of our database. We should have more than enough
RAM
to fit everything into memory. I would like to find out if I could
expect better performance by mounting the database from a RAM disk,
or
if I would be better off keeping that RAM free and increasing the
effective_cache_size appropriately.
If you're accessing a dedicated, read-only system with a database
small
enough to fit in RAM, it'll all be cached there anyway, at least on
Linux
and BSD. You won't be gaining anything by creating a ramdisk.
ditto windows.
Files cached in memory are slower than reading straight from memory
but
not nearly enough to justify reserving memory for your use. In other
words, your O/S is a machine with years and years of engineering
designed best how to dole memory out to caching and various processes.
Why second guess it?
Because sometimes it gets it wrong. The most brutal method is
occasionally the most desirable. Even if it not the "right" way to do
it.
Merlin
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