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Date: Mon, 30 Jun 2025 08:36:13 +0100
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To: pgsql-admin@lists.postgresql.org
From: Achilleas Mantzios <a.mantzios@cloud.gatewaynet.com>
Subject: Fast Logical replication setup, via VM clone , PostgreSQL 16.9
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Hi,

I gotta provide again a logical repl subscriber for our devs, we are 
running PostgreSQL 16.9 .

Instead of going the traditional logical replication way (which involves 
long running COPY, catchup, etc), I am thinking of doing something along 
the lines :

1) @publisher (master) create repl slot, create publication

2) shutdown postgresql ,

3) clone the VM,

4) boot the clone (subscriber),

5) @subscriber start postgresql , drop publication, drop replication 
slot, create the subscription using repl slot of 1)

6) @master start postgresql .

or a version with less downtime for the publisher (aka master , primary) :

1) @publisher (master) create repl slot, create publication

2) shutdown postgresql ,

3) clone the VM,

4) start master,

5) boot the clone (subscriber),

6) @subscriber start postgresql , drop the publication, drop the 
replication slot, create the subscription using repl slot of 1)


do you find any gotchas in the above ?