s2geometry VS sled

I experimented with geospatial Hilbert Curves as a Postgres extension [0] for PostGIS using the S2 [1] spherical geometry library. S2 uses a scale free cell coverage pattern that is numbered using six interlocking space filling Hilbert Curves [2].

By having both high level (cell) and low level (cell id) geometries it was a very powerful library which allowed projection from the hilbert space into a Postgres spatial index (spgist) including various trees, like noted in this article. It appears to be still quite active in development.

[0] https://github.com/michelp/pgs2

[1] https://s2geometry.io/

[2] https://s2geometry.io/devguide/s2cell_hierarchy

If you check the h3geo comparison page, you should see plenty of alternatives to geohash, such as s2 or even h3 itself.

See some discussion I started at https://github.com/google/s2geometry/issues/190

> It was quite hard for me to find open-source implementations of linear quadtrees.

You probably know this, but the S2 library has one: https://github.com/google/s2geometry

https://s2geometry.io shows how this works

If your points are distributed globally, however, I'd suggest using something like s2geometry (calculates over a sphere instead of an ellipsoid which is much faster + already has something called S2ClosestPointQuery).

Some alternative solutions are S2 from Google and H3 from Uber. These don't have the same issues as geohash because they work on a 3-d model of the geoid and not a 2-d cylindrical projection like Geohash.

a few times, seems interesting. The author's also built a lot of other cool concurrency primitives for Rust as well.

[0] https://github.com/spacejam/sled

- Dropbox [3] uses a similar approach but they talk about it a bit more abstractly.

Sans-IO is more documented in Python [4], but str0m [5] and quinn-proto [6] are the best examples in Rust I’m aware of. Note that sans-IO is orthogonal to deterministic test frameworks, but it composes well with them.

With the disclaimer that my opinions are mine and mine alone, and don’t reflect the company I work at —— I do work at a rust shop that has utilized these techniques on some projects.

TigerBeetle is an amazing example and I’ve looked at it before! They are really the best example of this approach outside of FoundationDB I think.

[0]: https://risingwave.com/blog/deterministic-simulation-a-new-e...

[1]: https://risingwave.com/blog/applying-deterministic-simulatio...

[2]: https://dropbox.tech/infrastructure/-testing-our-new-sync-en...

[3]: https://github.com/spacejam/sled

[4]: https://fractalideas.com/blog/sans-io-when-rubber-meets-road...

[5]: https://github.com/algesten/str0m

[6]: https://docs.rs/quinn-proto/0.10.6/quinn_proto/struct.Connec...

Sled uses bw-tree actually https://github.com/spacejam/sled/wiki/sled-architectural-outlook

There is a valid argument to be made for threads over async in a large percentage of use cases where async is considered the default. If this is what you are referring to however, I don't think they ever referred to async as completely useless: https://github.com/spacejam/sled/issues/1123.

Have you looked into other pure-Rust databases as well, such as sled or GlueSQL which has an SQL interface on top of sled? I wonder how those would compare to Persy.

I'm not sure what you need. Are these of any use? https://github.com/meilisearch/heed https://github.com/spacejam/sled

There is also Sled but as I understand it that is being reworked to use the author's new DB core Marble

There are some databases like sled/FlashDB designed to be embedded to other applications even bare metal microcontrollers. But I do doubt the potential bussiness value of a pure embedded database.

https://github.com/spacejam/sled

To add transaction support, you probably need a good understanding of how the memtable works in Log Structured Merge trees: