Yes, I assumed bit expressions involved positive integers only indeed. I thought the bitwise operators required that. That's my only use-case for them in fact. Perhaps the OP want to look into [expression-based indexes](https://sqlite.org/expridx.html) and/or [partial indexes](https://sqlite.org/partialindex.html) instead? That does assume his (or her) `?` values have very low cardinality. Anyways, as I wrote, I was just thinking aloud.