Re: Linux max on shared buffers?

Curt Sampson wrote:
> On Wed, 10 Jul 2002, Martin Dillard wrote:
>
> > When I try to allocate 2 GB or more....
>
> If I recall correctly, under normal circumstances a process under
> Linux has an address space of only 2 GB. Therefore you will never
> be able to allocate more memory than that. I think there's a patch
> (maybe from SGI?) that lets you increase this to 3 GB, but at any
> rate it's always going to be well under 4 GB, no matter what you
> do, unless you move to a 64-bit processor.
>
> But really, as discussed just in the last week on this list, you want to
> allocate more like 10 MB or so to postgres' shared memory area. Then the
> rest of your memory will be used as buffer cache and you will be happy.
> If you want to know why, go back though the archives of this list.

Woh, 10MB is clearly too low. Remember, there is copying overhead of
moving data from the kernel to the PostgreSQL shared buffers.

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