> > How is the module name encoded in RDB$EXTERNAL_NAME?
>
> It's not. Language is specified. Database engine reads the
> RDB$LANGUAGE from the RDB$EXTERNAL_PROCEDURES, then reads the
> corresponding module from RDB$EXTERNAL_ENGINE:
>
> SELECT RDB$MODULE_NAME FROM RDB$EXTERNAL_ENGINE ee INNER JOIN
> RDB$EXTERNAL_PROCEDURES ep ON ee.RDB$LANGUAGE = ep.RDB$LANGUAGE
> WHERE
> RDB$EXTERNAL_NAME = ?

Sorry, should be

SELECT
ee.RDB$MODULE_NAME,
ep.RDB$EXTERNAL_NAME
FROM
RDB$EXTERNAL_ENGINE ee
INNER JOIN
RDB$EXTERNAL_PROCEDURES ep
ON
ee.RDB$LANGUAGE = ep.RDB$LANGUAGE
WHERE
RDB$PROCEDURE_NAME = ?

Roman