Re: Add min and max execute statement time in pg_stat_statement - Mailing list pgsql-hackers

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.

cheers

andrew