I don't think this is a very helpful or accurate statement. I would encourage people to actually investigate things for themselves. Generally you do trade some

I don't think this is a very helpful or accurate statement. I would encourage people to actually investigate things for themselves. Generally you do trade some performance (depending upon implementation, they can be closer to the metal so to speak ) for flexibility ( again depending upon implementation ). Consider this documentation from oracle, a very popular materialized view implementation: "When changes are made to the master table or master materialized view using DML, an internal trigger records information about the affected rows in the materialized view log. This information includes the values of the primary key, rowid, or object id, or both, as well as the values of the other columns logged in the materialized view log. This is an internal AFTER ROW trigger that is automatically activated when you create a materialized view log for the target master table or master materialized view. "