Perhaps my DBA-fu is limited, but what databases are doing soft real time materialized view maintenance? The big boys seems to do recomputation for materialized views rather than updating the materialized view on insert or update. I tried to google for this, but saw only research papers rather than implementation.

I know that in places I worked, Materialized views were mostly limited in the application realm because too many of them over enough data brought the DB to its knees.