Boss: dashboard layer
A dashboard reads one number per day. Stack the layers: a per-order view, a daily view on top, and a materialized copy that the dashboard reads. The final query reads mv_dash and must stay under 300 buffers.
task
Create views v_order_totals and v_daily(d, orders, revenue_cents) and materialized view mv_dash with v_daily's rows; the dashboard query on mv_dash must read under 300 buffers.