Re: idea: log_statement_sample_rate - bottom limit for sampling

On Sun, Aug 04, 2019 at 03:16:12PM -0400, Tom Lane wrote:
>Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>> OK, I have the revert ready. The one thing I'm wondering about is
>> whether we need to revert log_transaction_sample_rate too? I think it's
>> pretty much independent feature, so I think we can keep that. Opinions?
>
>Isn't the issue here the interaction between log_transaction_sample_rate
>and log_min_duration_statement?  Seems like we have that question
>regardless of whether log_statement_sample_limit exists.
>

No, that interaction only affects statement-level sampling.

For transaction-level sampling we do the sampling independently of the
statement duration, i.e. we when starting a transaction we determine
whether the whole transaction will be sampled. It has nothing to do with
the proposed log_statement_sample_limit.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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