Re: Upgrading postgres quickly, without downtime.

On Fri, 2023-02-17 at 15:01 +0530, Karthik Krishnakumar wrote:
> I have a number of pg servers(~100 (each with a couple of replicas, so 300
> clusters in total), each with ~2TB data) that is running version 10.
> I am planning on upgrading to PG 15 and looking for ways to get it done
> without downtime and quickly.
> There seem to be a couple of ways to do this -
> 1. dump/restore or upgrade -> but this causes downtime.
> 2. logical replication/pglogical -> this is going to be slow, adds additional
> load on the master, and it isnt recommended to do DDL during time.
>
> I do have daily backups of these databases.
> Is there a way I can use these daily backups to upgrade to 15 and sync the changes for the day alone?
> I can code in C/scripts, and know bit of internals and wanted to ask where to start on this.
> I am also open to any alternate ideas. 

Take 10 minutes downtime and use "pg_upgrade --link".

Yours,
Laurenz Albe