Redshift Materialized View doesn't incrementally refresh

You’re conceptualizing an incremental refresh wrong. Let’s say you set up an incremental refresh on a table, then remove all the rows from that table, and add the rows back in. When the view refreshes, it looks for changed data. All the data has now changed, so it’s no different than a full refresh. That’s what’s going to happen in your scenario.

The other issue is your conceptualizing of materialized views incorrectly. Look at pg_tables, it’ll show all the physical tables. You’ll notice that some start with mv_ these are what redshift uses under the hood to represent the physical table in a materialized view. Views are just pointers, they don’t “contain” data that can change. And even if u could I wouldn’t recommend pointing anything directly at an mv_ table, they might get randomly whacked or something. Mat views aren’t smart enough to go down the chain and say “oh I’m referencing view a that references view b that references table c, something in table c changes so I have to change something too” so they just do full refresh.