Thread: Is there any impact if "#wal_keep_segments = 0 " and"checkpoint_segments = 128" postgresql.conf file.

Hi All,

Is there any impact if  "#wal_keep_segments = 0 " and "checkpoint_segments = 128" postgresql.conf file. If yes,what is the imapct?

checkpoint_segments = 128 # in logfile segments, min 1, 16MB each
#checkpoint_timeout = 5min # range 30s-1h
#checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0
#checkpoint_warning = 30s # 0 disables
#wal_keep_segments = 0 # in logfile segments, 16MB each; 0 disables
wal_level = archive # minimal, archive, or hot_standby
archive_mode = off # allows archiving to be done

--
Regards,
Raghavendra Rao J S V

Raghavendra Rao J S V wrote:
> Is there any impact if  "#wal_keep_segments = 0 " and "checkpoint_segments = 128"
> postgresql.conf file. If yes,what is the imapct?

Yes.
- You will have fewer checkpoints requested by data modification activity.
- Crash recovery might take longer.

Yours,
Laurenz Albe
-- 
Cybertec | https://www.cybertec-postgresql.com



Re: Is there any impact if "#wal_keep_segments = 0 " and"checkpoint_segments = 128" postgresql.conf file.

From
"Jehan-Guillaume (ioguix) de Rorthais"
Date:
On Mon, 15 Oct 2018 09:46:47 +0200
Laurenz Albe <laurenz.albe@cybertec.at> wrote:

> Raghavendra Rao J S V wrote:
> > Is there any impact if  "#wal_keep_segments = 0 " and "checkpoint_segments
> > = 128" postgresql.conf file. If yes,what is the imapct?  
> 
> Yes.
> - You will have fewer checkpoints requested by data modification activity.
> - Crash recovery might take longer.

And considering wal_keep_segments, there is no impact on perf/recovery. This
mostly related to the standby replication lag allowed and some other solutions
exists (slots, archiving).


Thanks a lot. 

On Mon, 15 Oct 2018 at 14:43, Jehan-Guillaume (ioguix) de Rorthais <ioguix@free.fr> wrote:
On Mon, 15 Oct 2018 09:46:47 +0200
Laurenz Albe <laurenz.albe@cybertec.at> wrote:

> Raghavendra Rao J S V wrote:
> > Is there any impact if  "#wal_keep_segments = 0 " and "checkpoint_segments
> > = 128" postgresql.conf file. If yes,what is the imapct? 
>
> Yes.
> - You will have fewer checkpoints requested by data modification activity.
> - Crash recovery might take longer.

And considering wal_keep_segments, there is no impact on perf/recovery. This
mostly related to the standby replication lag allowed and some other solutions
exists (slots, archiving).


--
Regards,
Raghavendra Rao J S V
Mobile- 8861161425