Suggestion about logging only every n-th statement

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.vygen@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