On 04/10/14 12:10, Bruce Momjian wrote:
> On Sat, Oct 4, 2014 at 12:00:36PM +1300, Mark Kirkwood wrote:
>>> I don't think we can offer absolutely accurate tuning advice, but I'm
>>> sure we can give some guidance. Let me try.
>>>
>>
>> +1
>>
>> I think it is ok to document our reason for providing the new GUC -
>> along with that fact that it is a new one and we need more field
>> testing and benchmarks to provide comprehensive advice about how to
>> set - and recommend leaving it alone unless consult with
>> experts/this list etc.
>
> I predict that such a setting will remain in postgresql.conf for years
> with almost zero activity, as have other similar efforts.
>
Sure that *may* happen. In fact in my experience the vast majority of
our current GUCs are never altered in the field - however when you run
into a situation where a certain GUC solves your performance issue, then
that seldom used GUC really gets some love.
So altho I get your point about endless proliferation of 'em not being
cost free, I'd like to plug the other side of the argument too - having
the flexibility to adjust your Postgres installation to work well with
<random platform with annoying quirks> is the corresponding benefit.
In addition with the increasing use of cloud platforms - the situation
above is likely to become *more* common (Postgres in Openstack using
Ceph for volume storage is a case in point).
Cheers
Mark