Re: log_checkpoint's "0 transaction log file(s) added" is extremely misleading - Mailing list pgsql-hackers

From Fujii Masao
Subject Re: log_checkpoint's "0 transaction log file(s) added" is extremely misleading
Date
Msg-id CAHGQGwGOmPH9=LQot35h-TiEZ2P_boNqGKKU8uhES3KXfpQctw@mail.gmail.com
Whole thread Raw
In response to Re: log_checkpoint's "0 transaction log file(s) added" is extremely misleading  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Fri, Jan 22, 2016 at 11:33 AM, Andres Freund <andres@anarazel.de> wrote:
> On January 22, 2016 3:29:44 AM GMT+01:00, Simon Riggs <simon@2ndQuadrant.com> wrote:
>>On 22 January 2016 at 01:12, Andres Freund <andres@anarazel.de> wrote:
>>
>>> Hi,
>>>
>>> While in theory correct, I think $subject is basically meaningless

What about just changing "added" to "preallocated" to avoid the confusion?

>>> because other backends may have added thousands of new segments. Yes,
>>it
>>> wasn't the checkpointer, but that's not particularly relevant
>>> imo. Additionally, afaics, it will only ever be 0 or 1.
>>>
>>
>>Even better, we could make it add >1
>
> That'd indeed be good, but I don't think it really will address my complaint: We'd still potentially create new
segmentsoutside the prealloc call. Including from within the checkpointer, when flushing WAL to be able to write out a
page.

IMO it's more helpful to display such information in something like
pg_stat_walwriter view rather than checkpoint log message.

Regards,

-- 
Fujii Masao



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