TLDR; Answer to 1: it cannot know unless it looks up the parent table, but once it does that then the rest of the plan will be skipped because 0 rows. Answer to 2: yes that's the whole point of the
GROUP BY
restrictions on indexed views, to make efficient updates. Advise to add
INCLUDE (Amount)
to the non-clustered index, and possibly a filtered index
WHERE (STATUS = 'READY')
to the parent table —
Charlieface 10 hours ago