RisingWave Community - Why is there no significant improvement in query speed after adding indexes to materialized views?

Indexes in materialized views are not the same as ordinary indexes in general database systems. They are specifically used for joins, not point selects.
Max and min aggregations have a different implementation compared to other aggregators. They store all input data in a state store, which can affect query performance.
Materialized views do support deleting data, but it is not well-documented yet.
Consider using the append-only source feature to reduce the state size for min and max aggregations in materialized views.