Re: New GUC to sample log queries

On 05/31/2018 03:22 PM, Michael Paquier wrote:
> On Thu, May 31, 2018 at 02:37:07PM +0200, Adrien Nayrat wrote:
>> On 05/31/2018 03:34 AM, David Rowley wrote:
>>> On 31 May 2018 at 06:44, Adrien Nayrat <adrien(dot)nayrat(at)anayrat(dot)info> wrote:
>>>> Here is a naive SELECT only bench with a dataset which fit in ram (scale factor
>>>> = 100) and PGDATA and log on a ramdisk:
>>>> shared_buffers = 4GB
>>>> seq_page_cost = random_page_cost = 1.0
>>>> logging_collector = on (no rotation)
>>>
>>> It would be better to just: SELECT 1; to try to get the true overhead
>>> of the additional logging code.
>>
>> Right, I wonder why I didn't have the idea :)
>
> Using prepared statements help also in reducing the load with
> unnecessary planning.
> --
> Michael
>

Thanks, but the winner is Julien Rouhaud with only ";", I reach 115K TPS on my
laptop :)

Attached third version of the patch with documentation.

--
Adrien NAYRAT