Re: Mount database on RAM disk?

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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