Horton

Re: idea: log_statement_sample_rate - bottom limit for sampling

Tom Lane <tgl@sss.pgh.pa.us>

View thread
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Adrien Nayrat <adrien.nayrat@anayrat.info>, pgsql-hackers@lists.postgresql.org
Date: 2019-08-04T20:25:12Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Revert "Add log_statement_sample_rate parameter"

  2. Revert "Silence compiler warning"

Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> On Sun, Aug 04, 2019 at 03:16:12PM -0400, Tom Lane wrote:
>> Isn't the issue here the interaction between log_transaction_sample_rate
>> and log_min_duration_statement?

> No, that interaction only affects statement-level sampling.

OK, I was confusing the features.

> 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.

So, to clarify: our plan is that a given statement will be logged
if any of these various partial-logging features says to do so?

(And the knock on HEAD's behavior is exactly that it breaks that
independence for log_min_duration_statement.)

			regards, tom lane