Oracle view pulling data from schemas in different instances?

How can you create an Oracle view that reads开发者_开发技巧 data from two schemas in two different instances?

We know how to do this with two schemas in the same instance:

CREATE VIEW MYVIEW AS 
SELECT X,Y,Z FROM A.MYTABLE
UNION 
SELECT X,Y,Z FROM B.MYTABLE

But what if schemas A and B are in different Oracle instances?

You could create a database link: http://download.oracle.com/docs/cd/B28359_01/server.111/b28310/ds_concepts002.htm#ADMIN12092 and then do

CREATE VIEW MYVIEW AS  
SELECT X,Y,Z FROM A.MYTABLE 
UNION  
SELECT X,Y,Z FROM B.MYTABLE@<LinkName>