[whilo]

I see, so your problem was that you wanted to scan over all Datoms for one entity over a time period and you would have needed to have an EVAT index? In Datahike it would be fairly simple to add new indices like this.

Yes, access management must not incur a large overhead, that is why many systems have a separate restricted way to express and track rules. My hunch is that it still would be better to keep it in Datalog and specialize the query engine that it is fast on these (potentially restricted) rules and relations.