stride-db is an experimental persistent key-value store built around a
Strided Adaptive Radix Trie (SART), memory-mapped immutable storage, and
snapshot MVCC.
The intended read path is lock-free and allocation-free after a read transaction has been opened. Keys and values are returned as borrowed slices from immutable mappings when the on-disk representation permits it.
SART started from a future-work observation in the original Adaptive Radix Trees paper:
Another idea is to design a space-efficient radix tree which has nodes of equal size. Instead of dynamically adapting the fanout based on the sparseness of the keys, the number of bits used from the key should change dynamically, while the fanout stays approximately constant. Such a tree could also be used for data stored on disk.
stride-db explores that idea as a persistent, mmap-oriented key-value store,
combining fixed-size routing nodes with adaptive key strides and ephemeral
MVCC snapshots. The paper's companion idea—latch-free synchronization using
atomic primitives—inspires a later exploration of optimistic root publication.