Re: Add Postgres module info

On 12/12/24 10:44, Michael Paquier wrote:
> On Wed, Dec 11, 2024 at 10:39:38PM -0500, Tom Lane wrote:
>> Michael Paquier <michael(at)paquier(dot)xyz> writes:
>>> Presumably,
>>> the extra tracking can be done in dfmgr.c with more fields added to
>>> DynamicFileList to track the information involved.
>>
>> I wouldn't add any overhead to the normal case for this. Couldn't
>> we walk the list and re-fetch each module's magic block inside
>> this new function?
>
> Depends on how much we should try to cache to make that less expensive
> on repeated calls because we cannot unload libraries, but sure, I
> don't see why we could not that for each SQL function call to simplify
> the logic and the structures in place.
I want to say that 'cannot unload libraries' is a negative outcome of
the architecture. It would be better to invent something like
PG_unregister, allowing libraries to at least return a hook routine call
back to the system.
So, maybe it makes sense to design this feature with re-fetching
libraries, supposing it is already implemented somehow and elements of
the DynamicFileList may be removed.

--
regards, Andrei Lepikhov