Grant privileges on tables in other database

Question

Context

I want to grant privileges to a specific user, on the public schema in database mydb.

Currently, I connect as user postgres on database mydb, and run :

GRANT insert, update, delete, truncate ON ALL TABLES IN SCHEMA public TO myuser

My Issue

I would feel more comfortable naming the target database in the query, rather than relying on the connection being on the correct database.

For example, I wouldn't want to accidentally give accesses on the postgres database, rather than on mydb.

Question

Is there a way to target tables in another database in a GRANT query ?

I couldn't find a way to do so in the doc (perhaps I overlooked a paragraph ?) and the following do not work :

# grant insert on all tables in schema mydb.public to myuser;
ERROR:  syntax error at or near "."
LINE 1: grant insert on all tables in schema mydb.public to...
                                                          ^
# grant insert on mydb.public.mytable1 to myuser;
ERROR:  cross-database references are not implemented: "mydb.public.mytable1"

Answer 1

No, as the error message says, cross-database references are not implemented.

This is a security feature: There is no way to affect another database than the one you are connected to with an SQL statement (unless you are using something like dblink or foreign data wrappers).