Select the materialized view for maintaining in the object pane. Right-click and select the Maintain from the popup menu.
Enable Row Movement
To enable row movement.
Shrink
To compact the materialized view segment. By default, Oracle Database compacts the segment, adjusts the high water mark, and releases the recuperated space immediately.
Compile
To explicitly revalidate a materialized view. If an object upon which the materialized view depends is dropped or altered, then the materialized view remains accessible, but it is invalid for query rewrite. You can choose this option to explicitly revalidate the materialized view to make it eligible for query rewrite.
Force Refresh
To perform a refresh.