It's principled that Mentat refuses to aggregate over general refs -- what meaning could sum(?e) have -- but not maximally helpful that I can't find the "latest" transaction ?tx directly. This ticket tracks trying to improve that, perhaps by adding latest and earliest synonyms for max, respectively min that apply just to transaction refs. Although I don't think we track whether a ref is a transaction ref throughout the query engine at this time, so it might be difficult to determine. But we have tx-before and tx-after, although I see no actual guarantee these aren't used for general refs.
It's principled that Mentat refuses to aggregate over general refs -- what meaning could
sum(?e)have -- but not maximally helpful that I can't find the "latest" transaction?txdirectly. This ticket tracks trying to improve that, perhaps by addinglatestandearliestsynonyms formax, respectivelyminthat apply just to transaction refs. Although I don't think we track whether a ref is a transaction ref throughout the query engine at this time, so it might be difficult to determine. But we havetx-beforeandtx-after, although I see no actual guarantee these aren't used for general refs.