Re: SQL objects UNITs (was: Extension Templates S03E11)

Stephen Frost escribió:
> * Dimitri Fontaine (dimitri@2ndQuadrant.fr) wrote:

> > Basically with building `UNIT` we realise with hindsight that we failed to
> > build a proper `EXTENSION` system, and we send that message to our users.
> 
> Little difficult to draw conclusions about what out 'hindsight' will
> look like.

I haven't been keeping very close attention to this, but I fail to see
why extensions are so much of a failure.  Surely we can invent a new
"kind" of extensions, ones whose contents specifically are dumped by
pg_dump.  Regular extensions, the kind we have today, still wouldn't,
but we could have a flag, say "CREATE EXTENSION ... (WITH DUMP)" or
something.  That way you don't have to come up with UNIT at all (or
whatever).  A whole new set of catalogs just to fix up a minor issue
with extensions sounds a bit too much to me; we can just add this new
thing on top of the existing infrastructure.

I didn't much like the WITH UNIT/END UNIT thingy.  What's wrong with
CREATE foo; ALTER EXTENSION ADD foo?  There's a bit of a problem that if 
you create the object and die before being able to add it to the
extension, it would linger unreferenced; but that's easily fixable by
doing the creation in a transaction, I think.  (Alternatively, we could
have a single command that creates the extension and the contained
objects in one fell swoop, similar to how CREATE SCHEMA can do it; but
I'm not sure that's all that much better, and from a grammar POV it
probably sucks.)

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
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