Message-ID: <61b6cfb6ae03b5ad6512d0d167a5cb409ae58f21.camel@cybertec.at>
Subject: Re: PostgreSQL Upgrade (v9.5 to v12) with Django 2.0
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Kushal Shri <shrikushalk@gmail.com>, pgsql-admin@lists.postgresql.org
Date: Thu, 12 Jun 2025 15:19:37 +0200
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On Wed, 2025-06-11 at 16:39 +0545, Kushal Shri wrote:
> We are in the process of planning a PostgreSQL upgrade and would greatly
> appreciate any insights, best practices, or lessons learned from your exp=
eriences.
>=20
> Current Setup:
> =C2=A0 =C2=A0- PostgreSQL version: 9.5
> =C2=A0 =C2=A0- Django version: 2.0
> =C2=A0 =C2=A0- Database size: ~3 TB
> =C2=A0 =C2=A0- One Master 4 Replicas(Streaming Replication)
>=20
> We are taking a phased approach to this upgrade. In Phase 1, our goal is =
to
> upgrade PostgreSQL from v9.5 to v12, ensuring compatibility with our curr=
ent
> Django 2.0 application.

That's already wrong.  PostgreSQL v12 is out of support.  Upgrade to v17 or=
 v18.

> As part of this, I would like to understand:
>=20
> - What is the highest PostgreSQL version reliably supported with Django 2=
.0?

You'll have to ask Django what they support.

> - What upgrade strategies or methods have worked well for you in similar =
environments?

pg_upgrade --link

> - Any gotchas or performance considerations to keep in mind with large da=
tabases
>   during such upgrades?

Make sure you don't have millions of Large Objects, otherwise the upgrade
will be very slow and memory consuming.

Yours,
Laurenz Albe