I’m really curious how this works and how it’s implementation compares to something like materialize — I wonder if there are any caveats around consistency
In short, it can be compared in consistency to an up-to-date read replica; PlanetScale Boost uses Vitess' VStream to process events as they happen and keep itself up to date. The blog has much more information if you're curious.
> Noria is a new streaming data-flow system designed to act as a fast storage backend for read-heavy web applications based on Jon Gjengset's Phd Thesis, as well as this paper from OSDI'18. It acts like a database, but precomputes and caches relational query results so that reads are blazingly fast. Noria automatically keeps cached results up-to-date as the underlying data, stored in persistent base tables, change. Noria uses partially-stateful data-flow to reduce memory overhead, and supports dynamic, runtime data-flow and query change.