Re: Suggestion about logging only every n-th statement

2018-06-24 Thread Adrien Nayrat
On 06/20/2018 03:06 PM, Janning Vygen wrote:
>> FYI in made this patch which seems do what you want :
>> https://www.postgresql.org/message-id/flat/c30ee535-ee1e-db9f-fa97-146b9f62caed%40anayrat.info#c30ee535-ee1e-db9f-fa97-146b9f62c...@anayrat.info
>>
>>
>> I will add an entry in september's commit fest.
> 
> excellent. Exactly what I want!

FYI, I added an entry in next commit fest (september is not open) :
https://commitfest.postgresql.org/18/1691/

Feel free to review it ;)

Regards,

-- 
Adrien NAYRAT



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Re: Suggestion about logging only every n-th statement

2018-06-20 Thread Adrien Nayrat
On 06/20/2018 03:08 PM, Andreas Kretschmer wrote:
> I would suggest using of pg_stat_statements for that.

I agree, but sometimes it is not sufficient. For example, if you need query's
parameters.

-- 
Adrien NAYRAT




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Re: Suggestion about logging only every n-th statement

2018-06-20 Thread Andreas Kretschmer
On 20 June 2018 13:51:25 CEST, Janning Vygen  wrote:
>Back in 2009 I made a suggestion which is not implemented yet but would
>
>still be very valuable and easy to implement in my opinion (not for me 
>as I am not speaking C):
>
>https://www.postgresql.org/message-id/flat/200903161426.56662.vygen%40kicktipp.de#200903161426.56662.vy...@kicktipp.de
>
>We still can't afford to log each and every statement as we have too 
>many and we don't want to afford more disk performance/space. Therefore
>
>we log only statements slower than 50ms.
>
>But for analyzing usage patterns it would be very nice to have this 
>combined with a sample_rate for logging.
>
>   logging_sample_rate = n
>
>So each n-th statement will get logged regardless of execution time.
>
>What do you think?
>
>regards
>Janning

I would suggest using of pg_stat_statements for that.

Regards, Andreas


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2ndQuadrant - The PostgreSQL Support Company



Re: Suggestion about logging only every n-th statement

2018-06-20 Thread Janning Vygen

Am 20.06.2018 um 14:53 schrieb Adrien NAYRAT:

On 06/20/2018 01:51 PM, Janning Vygen wrote:
Back in 2009 I made a suggestion which is not implemented yet but 
would still be very valuable and easy to implement in my opinion (not 
for me as I am not speaking C):


https://www.postgresql.org/message-id/flat/200903161426.56662.vygen%40kicktipp.de#200903161426.56662.vy...@kicktipp.de 



FYI in made this patch which seems do what you want :
https://www.postgresql.org/message-id/flat/c30ee535-ee1e-db9f-fa97-146b9f62caed%40anayrat.info#c30ee535-ee1e-db9f-fa97-146b9f62c...@anayrat.info 



I will add an entry in september's commit fest.


excellent. Exactly what I want!

regards
Janning




Re: Suggestion about logging only every n-th statement

2018-06-20 Thread Geoff Winkless
On Wed, 20 Jun 2018 at 12:51, Janning Vygen  wrote:

> But for analyzing usage patterns it would be very nice to have this
> combined with a sample_rate for logging.
>
>logging_sample_rate = n
>
> So each n-th statement will get logged regardless of execution time.
>

I think you would need to introduce a randomizing element ​if you wanted to
make it statistically valid. Logging every n'th statement could (depending
on your usage pattern) be catastrophically inaccurate.

Geoff