Re: ALTER EXTENSION DROP FUNCTION not working ?

Sandro Santilli <strk(at)keybit(dot)net> writes:
> On Tue, Feb 09, 2016 at 10:33:42AM +0100, Sandro Santilli wrote:
>> https://trac.osgeo.org/postgis/ticket/3450#comment:23
>>
>> Basically I'm getting:
>> ERROR: cannot drop function pgis_twkb_accum_finalfn(internal) because other objects depend on it
>> DETAIL: extension postgis depends on function pgis_twkb_accum_finalfn(internal)

> Figured: the "pgis_twkb_accum_finalfn(internal)" function is not
> a _direct_ dependency of extension "postgis", but is needed for
> an aggregate which is still registered.

> So this is more an annoyance than a bug, being the non-clear error
> message about what's the direct dependent object that prevents
> the drop.

I believe this is an intentional design decision: if you try to drop
something that an extension member object depends on, we complain about
the extension, not about the member object. This is on the grounds
that a user of an extension likely doesn't know or care exactly what
all the extension members are, and would rather think of the extension
as a unit. Consider for example that if you'd said CASCADE, the command
would have led to dropping the whole extension; would you want each
member object of the extension to be called out explicitly as a drop
cascade target?

I agree that it's a bit unintuitive when you're the developer of the
extension, but I doubt we're going to revisit this choice.

regards, tom lane