Hi There;
http://docs.oracle.com/cd/B10500_01/server.920/a96520/mv.htm
At that link, there is a phrase as such:
When you drop a materialized view that was created on a prebuilt table, the table still exists--only the materialized view is dropped.
When a prebuilt table is registered as a materialized view and query rewrite is desired, the parameter QUERY_REWRITE_INTEGRITY must be set to at least stale_tolerated because, when it is created, the materialized view is marked as unknown. Therefore, only stale integrity modes can be used.
What is prebuilt table? Thanks in advance.