What is the Red-X symbol beside a materialized view name in the Schema Browser | Materialized Views Tab? How can I remove it or make it disappear?
The Red X appears when data changes have occurred on the original table the Materialized View (MV) points to.
To remove the Red X beside your MV, try right-clicking your MV and choose “Refresh”. This should remove the Red X. Also if you use the refresh type for your MV script as “REFRESH FORCE ON COMMIT” (FORCE or FAST or COMPLETE) and make data changes on the original table and perform a Commit transaction, your MV is also automatically refreshed and thus no Red X will appear.