Good catch, but what you're saying is at least what I was trying to convey. Still doing it like this would mean two potentially larger index lookups plus calcul

Good catch, but what you're saying is at least what I was trying to convey. Still doing it like this would mean two potentially larger index lookups plus calculating the intersection between them rather than satisfying the filter from one index alone - for fetching the rows, it will be equivalent from there on of course. Still, I may have overstated the cost - I admit didn't even try separate indices in this case.