fdb-document-layer VS mvsqlite

This is exactly what the engineers behind FoundationDB (FDB) wanted when they open sourced. For those who don't know, FDB provides a transactional (and distributed) ordered key-value store with a somewhat simple but very powerful API.

Their vision was to build the hardest parts of building a database, such as transactions, fault-tolerance, high-availability, elastic scaling, etc. This would free users to build higher-level APIs (Layers) APIs [1] / libraries [2] on top.

The beauty of these layers is that you can basically remove doubt about about the correctness of data once it leaves the layer. FoundationDB is one of the most (if not the) most tested databases out there. I used it for over 4 years in high write / read production environments and never once did we second guess our decision.

I could see this project renamed to simply "fdb-sqlite-layer"

[1] https://github.com/FoundationDB/fdb-document-layer

https://github.com/FoundationDB/fdb-document-layer .and you get the transaction Al integrity.

I stopped using MongoDB and switched to this.

I’ve been using FDB for toy projects for a while. It’s truly rock solid. That being said, I wish there were more layers.

Ideally someone could implement the firestore or dynamodb api on top.

https://github.com/losfair/mvsqlite

For the rough plan, it's Cloud Backed SQLite meets FoundationDB.

- Oh, and if you're wondering about backup to S3, they have that too: https://github.com/libsql/bottomless

- Uh, sqld can integrated with this https://github.com/losfair/mvsqlite, so now your SQLite is backed by FoundationDB!?

- Meanwhile Litestream exists https://github.com/benbjohnson/litestream/

Shameless plug of my [mvSQLite](https://github.com/losfair/mvsqlite) project here! It's basically another distributed SQLite, but with support for everything expected from a proper distributed database: synchronous replication, strictly serializable transactions, + scalable reads and writes w/ multiple concurrent writers.

This project looks really exciting!

I'm working on mvsqlite [1], a distributed SQLite based on FoundationDB. When doing the VFS integration I have always wanted to patch SQLite itself, but didn't because of uncertainty around correctness of the patched version...

A few features on my wishlist:

1. Asynchronous I/O. mvsqlite is currently doing its own prefetch prediction that is not very accurate. I assume higher layers in SQLite have more information that can help with better prediction.

2. Custom page allocator. SQLite internally uses a linked list to manage database pages - this causes contention on any two transactions that both allocate or free pages.

3. Random ROWID, without the `max(int64)` row trick. Sequentially increasing ROWIDs is a primary source of contention, and causes significant INSERT slowdown in my benchmark [2].

[1] https://github.com/losfair/mvsqlite

[2] https://univalence.me/posts/mvsqlite-bench-20220930

That DynamoDB VFS looks cool! I agree that the VFS api makes one think about plenty of crazy ideas. Someone is working on a VFS based on Foundation DB[0] that looks very promising. It was recently discussed here[1]

[0]: https://github.com/losfair/mvsqlite

[1]: https://news.ycombinator.com/item?id=32269287