Hi @courajs
I’ll point you to a couple of choice quotes from our docs on qseq and confirm for you that your first assumption is correct. Qseq determines all entity ids immediately, then lazily pulls.
https://docs.datomic.com/cloud/query/query-executing.html#qseq
Item transformations such as ‘pull’ are deferred until the seq is consumed
And
qseq is a variant of q that pulls and xforms lazily as you consume
Thanks,
Jaret