IIIUC the fundemental datamodel here is a log of changes. A "query engine" is layered on top to get reasonable query performance, but that amounts to maintainin

IIIUC the fundemental datamodel here is a log of changes. A "query engine" is layered on top to get reasonable query performance, but that amounts to maintaining a materialized view for any data that might want to be queried. Otherwise the blockchain itself is not practically queriable by itself.