The SQL-MED specification defines the IMPORT FOREIGN SCHEMA statement.
This adds discoverability to foreign servers. The structure of the statement as I understand it is simple enough:
IMPORT FOREIGN SCHEMA remote_schema FROM SERVER some_server [ (LIMIT TO | EXCEPT) table_list ] INTO local_schema.
Is anyone working on this? I found a reference to this from 2010 in the archive, stating that work should be focused on core functionality, but nothing more recent.
This would be very useful for postgres_fdw and other RDBMS-backed fdws, but I think even file_fdw could benefit from it if it was able to create a foreign table for every csv-with-header file in a directory.
I can see a simple API working for that. A new function would be added to the fdw routine, which is responsible for crafting CreateForeignTableStmt. It could have the following signature:
typedef List *(*ImportForeignSchema_function) (ForeignServer *server, ImportForeignSchemaStmt * parsetree);
I experimented with this idea, and came up with the attached two patches: one for the core, and the other for actually implementing the API in postgres_fdw.
Maybe those can serve as a proof-of-concept for discussing the design?
I havent had a look at the patch yet since I dont have a nice editor right now, but how do you handle inter operability between datatypes? Specifically, how do you handle those datatypes which have a different name from the PostgreSQL name for them and/or are stored in a different manner?
