Re: Clarification on when _PG_init() is invoked for extensions

Hi,

CREATE extension does not automatically load or ensure that _PG_init() is run.
It mainly runs the .sql script in your extension.  

Thanks for the clarification. However, in my testing, _PG_init() did run when I executed
CREATE EXTENSION. I suspect this might be happening because the SQL script defines
C functions using MODULE_PATHNAME, which triggers the library load.
In a new session, _PG_init() seems to run again when any of those C functions are executed.

My use case:

My use case is that I’m building an experimental extension that will be installed only in a few
databases. I want the hooks initialized by this extension to apply only to those specific
databases, while all other databases should continue with the default PostgreSQL behavior.

Thank you,
Ayush