On 17/02/15 03:03, Andrew Dunstan wrote:
>
> On 02/16/2015 08:57 PM, Andrew Dunstan wrote:
>>
>> On 02/16/2015 08:48 PM, Petr Jelinek wrote:
>>> On 17/02/15 01:57, Peter Geoghegan wrote:
>>>> On Mon, Feb 16, 2015 at 4:44 PM, Petr Jelinek <petr@2ndquadrant.com>
>>>> wrote:
>>>>> We definitely want this feature, I wished to have this info many
>>>>> times.
>>>>
>>>> I would still like to see a benchmark.
>>>>
>>>>
>>>
>>> Average of 3 runs of read-only pgbench on my system all with
>>> pg_stat_statement activated:
>>> HEAD: 20631
>>> SQRT: 20533
>>> SQRTD: 20592
>>>
>>>
>>
>>
>> So using sqrtd the cost is 0.18%. I think that's acceptable.
>>
>
> Actually, sqrt/sqrtd is not called in accumulating the stats, only in
> the reporting function. So it looks like the difference here should be
> noise. Maybe we need some longer runs.
>
Yes there are variations between individual runs so it might be really
just that, I can leave it running for much longer time tomorrow.
-- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training &
Services
