conn xxx/xxx
set verify off feedback off
set long 1000000000
set longc  1000000000
set head off
set wrap on
set linesize 10000
spool /home/oracle/dual.sql
select 'select dbms_metadata.get_ddl('||''''||'MATERIALIZED_VIEW'||''''||','||''''||mview_name||''''||') from dual;'||chr(10)||'select'||''''||'/'||''''||' from dual;' from all_mviews;
spool off
spool /home/oracle/ddl.sql
@dual.sql
spool off