[jabl]

There was a big project to re-architect the low level storage system to something that isn't dependent on vacuuming, called zheap. Unfortunately it seems to have stalled and nobody seems to be working on it anymore? I keep scanning the release notes for each new pgsql version, but no dice.

[qazxcvbnm]

I think OrioleDB is picking up from where zheap left things, and seems quite active in upstreaming their work, you might be interested to check it out.