How does it compare to https://slatedb.io/ ?

Seems similar ideas, although SlateDB seems a bit more lightweight and using Parquet as primitive (even using Arrow) might mean more compute-heavy on client-side?

Sounds very interesting, but the README has me pondering the downsides. Is the latency very high? Are requests not immediately durable? Is it super expensive?

This is so weird. If you're using this library

1) your serverless and edge runtime needs to have internet access, so it can contact anyone

2) you're obviously not going to be able to efficiently write to S3 while providing guarantees, so it'll be expensive

3) you're writing in rust, so you really care about correctness and efficiency

This seems like a contradiction. Why would you do this as opposed to hosting a redundant postgres on 2 Hetzner/OVH/... servers and writing to that?

License does not yet exist? Hope it’s Apache 2.