Comment by ftdyuio9p0iugy

I've had some append-only tables in Postgres and only recently realised that Postgres' system columns (https://www.postgresql.org/docs/14/ddl-system-columns.html) already effectively enabled some Datomic-like structure for such append-only tables! Specifically the xmin column allows me to identify the rows to treat atomically as a unit, and to ignore if I'm querying for a historical view.