On 21st of October, Robert Haas committed patch: postgres_fdw: Push down aggregates to remote servers. Now that the upper planner uses paths, and now that we have proper hooks to inject paths into the upper planning process, it's possible for foreign data wrappers to ...

On 18th of March, Robert Haas committed patch: Directly modify foreign tables. postgres_fdw can now sent an UPDATE or DELETE statement directly to the foreign server in simple cases, rather than sending a SELECT FOR UPDATE statement and then updating or deleting rows one-by-one. Etsuro ...

On 22nd of March, Tom Lane committed patch: Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, ...

On 10th of July, Tom Lane committed patch: Implement IMPORT FOREIGN SCHEMA. This command provides an automated way to create foreign table definitions that match remote tables, thereby reducing tedium and chances for error. In this patch, we provide the necessary core-server infrastructure and implement ...

On 10th of March, Tom Lane committed patch: Support writable foreign tables. This patch adds the core-system infrastructure needed to support updates on foreign tables, and extends contrib/postgres_fdw to allow updates against remote Postgres servers. There's still a great deal of room for improvement ...

Well, saying that on particular date someone committed patch, wouldn't be really telling. In fact various bits and pieces of underlying logic have been committed for a long time, but now we finally have some functionality visible and available to ...