Ok so, I kinda assumed that the query engine would only compute `all_species_ids_for_this_color` on the rows we actually returned, and it's a fast subquery so it's fine. But that was wrong! I think the query engine computing that for _every_ item, and _then_ filter out stuff with `HAVING`. Which makes sense, because the `HAVING` clause references it, so computing it makes sense!
In this change, we inline the subquery, so it only gets called if the other conditions in the `HAVING` clause don't fail first. That way, it only gets run when needed, and the query runs like 2x faster (~30sec instead of ~60sec), which gets us back inside some timeouts that were triggering around 1 minute and making the page fail.
However, this meant we no longer return `all_species_ids_for_this_color`, which we actually use to determine which species are _left_ to model for! So now, we have a loader that also basically runs the same query as that condition subquery.
A reasonable question would be, at this point, is the `HAVING` clause a good idea? would it be simpler to do the filtering in JS?
and I think it might be simpler, but I would guess noticeably worse performance, because I think we really do filter out a _lot_ of results with that `HAVING` clause—like basically all items, right? So to filter on the JS side, we'd be transferring data for all items over the wire, which… like, that's not even the worst dealbreaker, but it would certainly be noticed. This hypothesis could be wrong, but it's enough of a reason for me to not bother pursuring the refactor!
Matchu
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