On Fri, Feb 6, 2026 at 7:37 AM Florents Tselai
<[email protected]> wrote:
>
> Twice this week I've encountered users confusing wal_level=logical with the
> actual setup of Logical Replication.
> Since users often land directly on the config.html page via search engines,
> they see the setting and assume enabling it is all that is required for
> replication to work.
> I think adding a clarification note here will prevent this (not so uncommon)
> misunderstanding.
+ <note>
+ <para>
+ Setting <literal>wal_level=logical</literal> enables logical decoding.
+ It is a prerequisite for logical replication, but by itself
+ does not configure logical replication; see <xref
linkend="logical-replication"/>.
+ </para>
+ </note>
While I agree that it would be a good idea to mention logical
replication in the description of wal_level, the proposed change seems
not clear to me (specifically, what exactly means by "configure
logical replication"?). Given that we already mention logical decoding
in the description,
Finally, logical adds information necessary to support logical decoding.
How about adding logical replication with its link here? For example,
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index f670e2d4c31..64672e559fc 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3079,8 +3079,9 @@ include_dir 'conf.d'
logging except the information required to recover from a crash or
immediate shutdown. Finally,
<literal>logical</literal> adds information necessary to
support logical
- decoding. Each level includes the information logged at all lower
- levels. This parameter can only be set at server start.
+ decoding and <link linkend="logical-replication">logical
replication</link>.
+ Each level includes the information logged at all lower
levels. This parameter
+ can only be set at server start.
</para>
<para>
The <literal>minimal</literal> level generates the least WAL
While it's technically enough to mention only logical decoding as
logical replication is built on top of logical decoding, it's not
obvious for users. Explicitly adding the link to logical replication
might help users not to be confused.
Feedback is very welcome.
Regards,
--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com
