Re: SQL/MED compatible connection manager

> I have put together a draft that describes a possible implementation:
> http://wiki.postgresql.org/wiki/SqlMedConnectionManager
>

I'll update this with an experimental patch. This implements:
* System catalogs for FDW, SERVER and USER MAPPING
* regserver data type for servers (convert from text to oid etc).
* FDW placeholders as shared libraries -- currently provides dummy
  and pgsql wrappers.
* Connection lookup via FDW.
* SQL interface to the lookup function.

There is an example of how all this works at:
http://wiki.postgresql.org/wiki/SqlMedConnectionManager#Current_implementation

I was hoping to get the internal features done by the start of November
Commitfest. But right now this seems unlikely. Nevertheless, I'm all ears
for suggestions and criticism.

PS. Jonah, does this somehow coincide with your approach to FDW-s?

regards,
Martin