When attempting to validate a query that contains the database link, e.g. the Oracle syntax
select * from INV_INVESTMENTS@EXAMPLEDBLINK
16.3.3
16.4.0
This is by design.
Starting in 16.4.0, the on-the-fly query validation error message will be displayed:
This query cannot be validated.
DBLink is not supported in query string.
Any query referencing the database link will not be supported/permitted at this point in time.