Re: dblink get_connect_string() passes FDW option "updatable" to the connect string, connection fails.

Corey Huinker <corey(dot)huinker(at)gmail(dot)com> writes:
> I ran into this today:
> CREATE SERVER bob_srv FOREIGN DATA WRAPPER postgres_fdw OPTIONS ( host
> 'localhost', dbname :'current_db' );
> ...
> ALTER SERVER bob_srv OPTIONS (updatable 'true');
> SELECT *
> FROM dblink('bob_srv','SELECT 1') as t(x integer);
> psql:bug_example.sql:18: ERROR: could not establish connection
> DETAIL: invalid connection option "updatable"

> Is this something we want to fix?

The dblink docs recommend using dblink_fdw as the FDW for this purpose,
which would only accept legal connstr options. However, I can see the
point of using a postgres_fdw server instead, and considering that
dblink isn't actually enforcing use of any particular FDW type, it seems
like the onus should be on it to be more wary of what the options are.

It looks like this might be fairly easy to fix by having
get_connect_string() use is_valid_dblink_option() to check each
option name, and silently ignore options that are inappropriate.

regards, tom lane