Hi Hackers,

Currently, if there's a typo in an extension name while adding a GUC to 
postgresql.conf, PostgreSQL server starts up silently without any warning. This 
can be misleading, as one might assume the configuration has been correctly 
applied, when in fact the value hasn’t been set due to the typo.

To improve this experience, I’m proposing a patch that issues a warning for 
such invalid GUC entries. This can serve as a helpful acknowledgment, 
especially in cases where the mistake is unintentional (e.g., a simple typo).

For example, if I mistakenly add pg_stut_statements.max = 15000 (observe the 
typo in the extension name) to postgresql.conf and restart PostgreSQL, the 
server currently starts without indicating any issue. However, with this patch, 
the startup output will include a warning like:


WARNING:  invalid configuration parameter name "pg_stut_statements.max", 
removing it

2025-05-21 17:10:45 GMT::@:[44158]:DETAIL:  "pg_stut_statements.max" doesn't 
has a reserved prefix.







I believe providing such feedback during startup can be quite helpful for 
users, especially to catch and correct typos early.

Please find the attached patch for your consideration.






Thanks & Regards,

Shaik Mohammad Mujeeb

Member Technical Staff

Zoho Corp

Attachment: warn_and_remove_invalid_prefix_gucs.patch
Description: Binary data

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