From: Dean Gibson (DB Administrator) <postgresql@mailpen.com>
To: pgsql-performance@lists.postgresql.org
Subject: Re: Estimating wal_keep_size
Date: Sun, 20 Jun 2021 16:53:35 -0700
Message-ID: <9d4c8207-b05c-0d9a-30e8-1fab15d640a1@mailpen.com> (raw)
In-Reply-To: <471a6e7d-928e-c899-bf9f-341ae79b04ea@mailpen.com>
References: <471a6e7d-928e-c899-bf9f-341ae79b04ea@mailpen.com>
On 2021-06-16 17:36, Dean Gibson (DB Administrator) wrote:
> Is this reasonable thinking?
>
> I'd think that one would want a *wal_keep_size* to cover the pending
> updates while the standby server might be unavailable, however long
> one might anticipate that would be.
>
> In my case, I get a complete replacement (in the form of "|"-
> delimited ASCII files) of one of the SCHEMAs every Sunday. The size
> of that ASCII data is about 2GB, so I'm thinking of doubling that to
> 4GB (256 WAL files) to protect me in the case of the standby being
> unavailable during the update. Note that a complete loss of both
> servers is not catastrophic (I have backups); it would just be annoying.
>
In the absence of any clear guidance, I temporarily set wal_keep_size to
16GB & waited for the Sunday update. That update today created just
over 6GB of WAL files during the update, so I've set wal_keep_size to
8GB (512 WAL files).
Oh, and wal_keep_size is NOT an upper limit restricting further WAL
files. It's more like a minimum.
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: postgresql@mailpen.com, pgsql-performance@lists.postgresql.org
Subject: Re: Estimating wal_keep_size
In-Reply-To: <9d4c8207-b05c-0d9a-30e8-1fab15d640a1@mailpen.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox