[evanelias]

Interesting, thanks! Indeed, there isn't an equivalent feature in MySQL yet.

Out of curiosity, how commonly is this used at scale? I'd imagine there are significant trade-offs with write amplification, meaning it would consume a lot of space and make writes slow. (vs making indexes on specific expressions, I mean. That said, you're right -- there are definitely use-cases where making indexes on specific expressions isn't practical or is too inflexible.)