Create foreign table on file_fdw as non-superuser

Question

I have created a file_fdw extension and a corresponding server as superuser.

CREATE EXTENSION file_fdw;
CREATE SERVER myserver FOREIGN DATA WRAPPER file_fdw;

ALTER SERVER myserver OWNER TO nonsuperuser;

I want a non-superuser nonsuperuser to use this server to create a foreign table

CREATE FOREIGN TABLE test (
   a text NULL,
   b text NULL
)
SERVER myserver
    OPTIONS (filename '/home/me/mycsvfile.csv', format 'csv', header 'true', delimiter ';');

Executing this, leads to `only superuser can change options of a file_fdw foreign table

What can I do to enable nonsuperuser to create foreign tables? If possible I would not mind declaring the options as super user.

Answer 1

Only highly privileged users are allowed to access files on the database server, that's why you need high permissions to create a file_fdw foreign table.

From the error message it becomes clear that you are using an old version of PostgreSQL; on more recent versions, the error message would look like:

only superuser or a member of the pg_read_server_files role may specify the filename option of a file_fdw foreign table

So, as an alternative to dealing out superuser privileges, you may add the user to the pg_read_server_files role.

Upgrade PostgreSQL!