Learned Index Lab: Replacing B-Trees with streaming linear models in pure Rust (-99% RAM, 3x faster)

[u/gilnett]

https://github.com/gilnett/learned_index_lab

Instead of pointer-chasing through B-Tree node hierarchies, this index models the key distribution using streaming piecewise linear regression with strict epsilon error bounds.

Lookups compute positions directly on the CPU ALU before a local L1 cache search, reducing memory by 99% and cutting latency by 3x.