Horton

Re: New GUC to sample log queries

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Michael Paquier <michael@paquier.xyz>, Dmitry Dolgov <9erthalion6@gmail.com>
Cc: adrien.nayrat@anayrat.info, Vik Fearing <vik.fearing@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, david.rowley@2ndquadrant.com, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-01-04T12:16:48Z
Lists: pgsql-hackers 
On 19/11/2018 14:40, Tomas Vondra wrote:
> On 11/19/18 2:57 AM, Michael Paquier wrote:
>> On Sun, Nov 18, 2018 at 12:18:33PM +0100, Dmitry Dolgov wrote:
>>> Since it's hard to come up with a concise name that will mention sampling rate
>>> in the context of min_duration_statement, I think it's fine to name this
>>> configuration "log_sample_rate", as long as it's dependency from
>>> log_min_duration_statements is clearly explained in the documentation.
>>
>> log_sample_rate looks fine to me as a name.
> 
> That seems far too short to me - the name should indicate it applies to 
> statement logging. I'd say log_statement_sample_rate is better.

It was committed with this name, but then one has to wonder why it
doesn't also apply to log_statement.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Use pg_strong_random() to select each server process's random seed.

  2. Use a separate random seed for SQL random()/setseed() functions.

  3. Marginal performance hacking in erand48.c.

  4. Fix latent problem with pg_jrand48().

  5. Silence compiler warning

  6. Add log_statement_sample_rate parameter