Re: doc: Improve wal_level and effective_wal_level GUC around logical replication

Andreas Karlsson <andreas@proxel.se>

From: Andreas Karlsson <andreas@proxel.se>
To: "David G. Johnston" <david.g.johnston@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-04-07T21:59:24Z
Lists: pgsql-hackers
On 3/4/26 4:55 PM, David G. Johnston wrote:
> In evaluating the proposed change to wal_level docs in [1] I found it to 
> be undesirable, but the discussion and my own review discovered some 
> other changes that should be considered.

While I am not happy with the text before I am not sure your changes 
here really make it much better, just different, hmm.

> Since effective_wal_level now exists, Logical Replication Getting 
> Started needs to be updated.
> Add links to the main topics that the different levels apply to.
> Be explicit about the ordering of minimal, replica, and logical.
> Move the behavior of effective_wal_level to the GUC for it, leaving 
> behind just the pointer that wal_level is now just a "minimum".
Shouldn't it be:

"Ensure that <xref linkend="guc-wal-level"/> is at least replica"

and

"wal_level = replica"

as the logical replication slot may be created later?

-- 
Andreas Karlsson
Percona