ORA-1555 During Materialized View Create or Refresh 

When executing a Materialized View refresh an ORA-01555 is returned.  This returns the following type of error either in the alert.log : There are several solutions that can assist here, outside of the normal UNDO Tuning practices from the note above: 1. Increase the UNDO_RETENTION parameter beyond the threshold seen from the alert.log message for … Read more