Re: checkpoint_timout with no WAL activity - Mailing list pgsql-general

From Tom DalPozzo
Subject Re: checkpoint_timout with no WAL activity
Date
Msg-id CAK77FCS=SwLoWK0R=stxB30BPUvtqM3MXrT2Y46FXhqR2WUKjA@mail.gmail.com
Whole thread Raw
In response to Re: checkpoint_timout with no WAL activity  (amul sul <sulamul@gmail.com>)
Responses Re: checkpoint_timout with no WAL activity  (Michael Paquier <michael.paquier@gmail.com>)
List pgsql-general
I know that, but with neither database activity or chekpoint, it doesn't force anything. The fact is that there are checkpoints being executed every checkpoint_timeout, and I don't understand why as if no WAL has been written we should not care about passing the timeout.
Regards
Pupillo





2016-11-07 13:14 GMT+01:00 amul sul <sulamul@gmail.com>:
On Mon, Nov 7, 2016 at 4:20 PM, Tom DalPozzo <t.dalpozzo@gmail.com> wrote:
> Hi,
> I have:
> checkpoint_timeout = 2min
> wal_level = archive
> archive_mode=on
> archive_timeout = 30
>
> With NO dbase activity, I see the WAL being modified every 2min (and,
> consequently, one WAL file archived every 2min too ).
>
> Is it right? I read: "If no WAL has been written since the previous
> checkpoint, new checkpoints will be skipped even if checkpoint_timeout has
> passed."

I guess archive_timeout forcing to switch new WAL file, see this :
https://www.postgresql.org/docs/devel/static/runtime-config-wal.html#GUC-ARCHIVE-TIMEOUT

Regards,
Amul

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