See the SQL create definition of a materialized view by running this SQL:
set long 200000 pages 0 lines 131 doc off column txt format a121 word_wrapped spool recreate_sql select dbms_metadata.get_ddl('MATERIALIZED_VIEW','my_mv_name','my_owner') txt from dual; spool off set pages 9999
Look especially for the refresh option, e.g.:
REFRESH FORCE ON DEMAND NEXT null
There are three normally used refresh options:
- Fast = use materialized view logs on source
- Complete = ignore materialized view logs, instead truncate the materialized view and repopulate it from the base tables of source.
- Force = exactly the same as Fast – except when there are no materialized view logs on source, in which case it does a complete refresh.