Foreign servers and user mappings versus the extensions patch

On Sat, Feb 5, 2011 at 5:41 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Currently, the extensions patch considers that foreign data wrappers,
foreign servers, and user mapping objects can all be parts of extensions.
This is slightly problematic for pg_dump, where somebody decided to take
a shortcut and not implement user mappings using the full DumpableObject
infrastructure.  That could be fixed, but I'm wondering whether it's
worth the trouble.  I can see the point of writing an FDW as an
extension but it's a lot harder to see why either foreign server or user
mapping objects would ever be part of an extension.  So it might just be
best to remove those two object types from the set that can be managed
by an extension.

Comments?

I agree it's probably not that useful to make a foreign server or
foreign user mapping part of an extension, but I'd rather not have us
fail to support it just because we can't think of a use case right
now. So my vote would be to fix it.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Robert Haas <robertmhaas@gmail.com> writes:

On Sat, Feb 5, 2011 at 5:41 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Currently, the extensions patch considers that foreign data wrappers,
foreign servers, and user mapping objects can all be parts of extensions.
This is slightly problematic for pg_dump, where somebody decided to take
a shortcut and not implement user mappings using the full DumpableObject
infrastructure.  That could be fixed, but I'm wondering whether it's
worth the trouble.  I can see the point of writing an FDW as an
extension but it's a lot harder to see why either foreign server or user
mapping objects would ever be part of an extension.  So it might just be
best to remove those two object types from the set that can be managed
by an extension.

Comments?

I agree it's probably not that useful to make a foreign server or
foreign user mapping part of an extension, but I'd rather not have us
fail to support it just because we can't think of a use case right
now. So my vote would be to fix it.

I would have though that it could allow you to distribute internally at
the system level the user mappings and server details, then have a DBA
install it without exposing them the password or other details. Well, I
don't recall offhand what you see as a superuser in the system view, but
that could be a use case.

Other than that, I confess I added the support just to try at being
exhaustive.

Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support