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

Started by Raghavendra Rao J S Vover 7 years ago4 messagesgeneral

raghavendrajsv@gmail.com

over 7 years ago

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

Laurenz Albe

laurenz.albe@cybertec.at

over 7 years ago

In reply to: Raghavendra Rao J S V (#1)

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

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

Jehan-Guillaume (ioguix) de Rorthais

ioguix@free.fr

over 7 years ago

In reply to: Laurenz Albe (#2)

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

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).

Raghavendra Rao J S V

raghavendrajsv@gmail.com

over 7 years ago

In reply to: Jehan-Guillaume (ioguix) de Rorthais (#3)

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

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