Phoenix Kiula <phoenix(dot)kiula(at)gmail(dot)com> wrote:
> Now, according to my reading in the PG manual and this list, a
> good recommended value for SHMMAX is
>
> (shared_buffers * 8192)
Where did you see that? The amount of data buffered is the number
of shared buffers * 8KB. Taking shared_buffers as a number of bytes
and multiplying by 8K makes no sense at all. Any documentation
which can be read to indicate that should be fixed.
Besides that, there is shared memory space needed besides the actual
buffered disk pages, so you're not looking at the whole picture once
you stop dealing with "bytes squared".
-Kevin