A lot of the structures we have - like the ones under Schema, are
specific for materialized views. In preparation to adding normal views,
rename them, so things are less confusing.
This is just the bare minimum that I needed to convince myself that this
approach will work. The only views that we support are slices of the
main table: no aggregations, no joins, no projections.
drop view is implemented.
view population is implemented.
deletes, inserts and updates are implemented.
much like indexes before, a flag must be passed to enable views.
