Ah go to sleep, wake up, and find the solution immediately. As always happens. Followed the steps here and the ec2 instance now has proper s3 permissions: https://forum.datomic.com/t/ion-deploy-fails-due-to-access-denied/685/6

In a recursive pull expression, is there a way to specify both the limit and the attributes ?

How do Datomic queries handle a relation binding input with a nil variable? e.g.,

[:find ?release
 :in $ [[?artist-name ?release-name]]
 :where [?artist :artist/name ?artist-name]
        [?release :release/artists ?artist]
        [?release :release/name ?release-name]]

;; args
[db [["John Lennon" "Mind Games"]
      ["Paul McCartney" nil]]]