The docs (https://docs.datomic.com/cloud/schema/schema-reference.html#entity-specs) clearly state that: • :db/ensure is a virtual attribute • it is not added to the database But after transacting the initial assertions of my domain entity with :db/ensure, I subsequently see a ref attribute on the entity:

(d/pull db '[*] 101155069759907)
=>
{:db/id 101155069759907,
 :db/ensure [#:db{:id 87960930222306, :ident :st.data-source/valid?}],
 :st.data-source/id #uuid "0dcff1a1-3785-45c2-846f-de72401ba810",
 :st.data-source/credentials #:db{:id 101155069759908},
 :st.data-source/type :st.data-source.type/tesla}

The referenced entity is in fact the entity I had previously transacted into my schema to support the "named" ensure:

{:db/ident        :st.data-source/valid?
  :db.entity/attrs [:st.data-source/id :st.data-source/type]}

Perhaps relevant: this is using dev-local.

I’ve seen it in datomic-pro also

First: thanks for the confirmation. I thought I was going crazy. Second, any idea of a work-around?

workaround?

It seems like Datomic is not recognizing the :db/ensure attribute as "special" and is instead creating a reference with that name.

are you seeing it not perform the ensure?

I'm not sure TBH -I had not gotten that far.

I just assumed I was doing something wrong. That's next on my list of exploring.

ok, my experience is it definitely does whatever assertions it’s supposed to do, it just happens to be written into the db

If it's written, that begs the question: is the opt-in permanent since the attr is permanent?

no

So I still need to assert it on subsequent txs... good to know.

The only oddity is that the :db/add is eventually materialized as a datom instead of being stripped, and that’s only odd because they said it wouldn’t be

you should still treat it like a “verb” instead of data

As usual, your knowledge and helpfulness are unparalled!

This is something we were coincidentally looking into this week already. Invariants are definitely enforced, just leaves some noise that nobody intended.

Good to know. And with that confidence, I'll happily move along!

Related threads: • https://forum.datomic.com/t/db-ensure-doesnt-seem-virtual/2296 • https://ask.datomic.com/index.php/681/why-does-db-ensure-appear-as-an-attribute-in-my-entities?show=938#a938