CREATE OR REPLACE FUNCTION DDI.DBLINK_DDL
RETURN CLOB
AUTHID CURRENT_USER
AS
v_meta_handle NUMBER;
v_meta_handle_trans NUMBER;
V_DOC CLOB;
V_Next_Doc CLOB;
V_LOB CLOB;
BEGIN

  v_meta_handle := DBMS_METADATA.OPEN('DATABASE_EXPORT');
  DBMS_METADATA.SET_FILTER(v_meta_handle, 'INCLUDE_PATH_EXPR','IN''DB_LINK''');
  DBMS_METADATA.SET_FILTER(v_meta_handle, 'NAME_EXPR','IN''EMACH''','SCHEMA');
  DBMS_METADATA.SET_FILTER(v_meta_handle, 'NAME_EXPR','IN''TESTDB.REGRESS.RDBMS.DEV.US.ORACLE.COM''','DB_LINK');
  v_meta_handle_trans:=DBMS_METADATA.ADD_TRANSFORM(v_meta_handle,'DDL');
  
 LOOP
    v_doc   := DBMS_METADATA.FETCH_CLOB(v_meta_handle);
    EXIT WHEN v_doc IS NULL;
    IF V_Lob is null then 
     v_lob   := v_doc;
    ELSE
     v_lob   := V_LOB || v_doc;
    END IF;
    -- When there are no more objects to be retrieved, FETCH_CLOB returns NULL.
 END LOOP;
   return v_lob;
   end;

 CREATE DATABASE LINK "TESTDB.REGRESS.RDBMS.DEV.US.ORACLE.COM"
   CONNECT TO "TEST" IDENTIFIED BY VALUES '05840660603E8D639998C728374A8BEA8F'
   USING '(DESCRIPTION = 
    (ADDRESS = 
      (PROTOCOL = TCP)
      (Host = 10.91.40.8)
      (Port = 1521)
    )
    (CONNECT_DATA = 
      (SID = TESTDB)
    )
  )'