redb VS sediment

I wrote redb (https://github.com/cberner/redb) using mmap, initially. However, I later removed it and switched to read()/write() with my own user space cache. I'm sure it's not as good as the OS page cache, but the difference was only 1.2-1.5x performance on the benchmarks I cared about, and the cache is less than 500 lines of code.

exposure of the redb builder functionalities.

redb has reached its 1.0 release. The file format is now gauranteed to be backward compatible, and the API is stable. I've run pretty extensive fuzz testing, but please report any bugs you encounter.

I'm just now updating the benchmarks in the readme with multi-threaded workloads :) https://github.com/cberner/redb/pull/576

redb, but that doesn't have a stable file format yet,

I also have to support web, so I'm considering a hybrid approach with a direct IndexedDB API there and something like sqlite, percy, sanakirja, or redb on native.

Nice list, but don’t forget persy, redb and sanakirja too!

check out https://github.com/cberner/redb! it is inspired by LMDB and has comparable performance, but is entirely built in rust!

Yup, the language is immature in some domains like data replication, compilation time, lifetime expressivity, not having a default async runtime and the incompatibility of all of them. But many of these domains are worked on and improved every day this is why I love this language so much. This is because there is space for improvement. I also hope that one day we will have a pure-Rust LMDB alternative that I can contribute to without fear of C.

they are, ya! I'm quite excited about that, and already have a PR open to use GATs. It's not enough to fix this issue though, because std needs to add support for LendingIterator too

This looks like it could have been inspired by BonsaiDB's recent problems. I think the authors are now trying to achieve something similar to your project with a new storage layer called Sediment (which will become a part of Nebari if successful).