grain

https://github.com/grainrb/grain

Grain keeps dashboard aggregates pre-computed and incrementally up to date inside your own Postgres database. You declare the grain of an aggregate once — tenant, time bucket and dimensions — and Grain maintains it with deltas driven by database triggers instead of recomputing everything on a schedule. No new infrastructure, no materialized view refresh storms, and a verify command that proves the aggregate still matches its source.