Re: BUG #7494: WAL replay speed depends heavily on the shared_buffers size

Hallo John,

On Wed, Aug 15, 2012 at 3:40 PM, John R Pierce <pierce(at)hogranch(dot)com> wrote:

> On 08/15/12 6:36 AM, Bruce Momjian wrote:
>
>> We warn against making shared buffers > 8GB, and this is perhaps another
>> good reason.
>>
>
> I generally keep it at no more than 2gb as I've never found any
> performance improvements going higher, on systems with 48gb ram, and had
> more than a few performance degradations with larger shared buffers.
>
>
we see up to 10x performance increase with bigger shared_buffers in case of
this database. Main database entities are about 20GB in size and we see
that performance drops considerably when running with smaller
shared_buffers smaller then that.

Regards,

-- Valentin