Filtering on an enum field in a foreign table

[Vladimir Ryabtsev <greatvovan@xxxxxxxxx>]

I am querying a remote server through a foreign table definition.

CREATE TABLE example (id integer, product product_enum, status status_enum)

Where

CREATE TYPE status AS ENUM ('active', 'testing', 'inactive', ...);

CREATE TYPE product AS ENUM ('a', 'b', 'c', ...);

I re-created enums on my server and created a foreign table as follows:

CREATE FOREIGN TABLE example (id integer, product product_enum, status status_enum)

SERVER remote;

When I am querying the foreign table on enum predicate like

select * from example where product = 'a' and status = 'active'

I see that filtering happens on my server which can be seen in the plan and can be felt from the query performance (indices are not used of course).

I tried to cheat this thing by defining the enum fields as text in the foreign table but then the remote query fails with

ERROR: operator does not exist: public.product = text HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.

This is ridiculous. Is there a way to workaround this and force it execute the remote query as is?

Regards,
Vlad