Hi, you might be thinking of another key-value store (FoundationDB maybe?). RocksDB can be linked as am embedded library so it doesn't need to run in a separate address space.
Coincidentially, SQL is having a "revival" in the streaming world... feldera, materialize, arroyo and many others are all betting on SQL as the language to express computation on moving data.
I didn't - I wanted to build something I could understand, and the rust implementation comes with a load of (reasonable) complexity, some resulting from the execution model, some from performance requirements.
stepping has 3 Zset implementations - in memory, sqlite and postgres. Currently considering whether to write a small rust one.
We do think so! (disclaimer: I'm a co-founder at Feldera)
To give some more background: We are trialing feldera with several industry/enterprise partners from different domains. Our core team also built differential datalog (https://github.com/vmware/differential-datalog) in the past. And while ddlog is used quite successfully in products today, we believe the many lessons we learned with ddlog will help us to build an even better continuous analytics platform. FYI our code is open-source at https://github.com/feldera/feldera if you'd like to try it out.
If you don't want to use malloc in a kernel, that is fine. However, you should at least consider having something similar. This can be as simple as finding the available memory in your system and writing a frame or slab allocator. It will make your life much easier. It would be interesting to see how easy it is to integrate your memory manager directly with the rust language.
The crate is also on https://crates.io/crates/dbsp