create public database link linkname
  connect as remoteuser identified by remotepassword
  using 'tnsname';


Database link created.

select * from t1@linkname;

        ID NAME
---------- ----------
         1 test
         2 foo
         3 bar

create materialized view local_t1
  build immediate
  refresh next sysdate + interval '2' minute
as
  select * from t1@linkname
/


select * from local_t1;

        ID NAME
---------- ----------
         1 test
         2 foo
         3 bar

-- Login to the other database, insert one row...
-- wait 2 minutes... Zzzzzz

select * from local_t1;

        ID NAME
---------- ----------
         4 puuh
         1 test
         2 foo
         3 bar

select mview_name,last_refresh_date from user_mviews;

MVIEW_NAME                     LAST_REF
------------------------------ --------
LOCAL_T1                       14:21:04