[phamilton]

I'm sad this project fizzled: https://github.com/losfair/mvsqlite

It had the fascinating property of being a full multi-writer SQL engine when using Page Level Conflict Checking. Even more fascinating: every single client itself becomes a writer.

[ncruces]

The way they got multi-writer working is a bit too adventurous for me.

It involves fiddling the database header to ensure you can keep track of the read-set from the VFS layer, by convincing SQLite to drop its page cache at the start of every transaction.

Other than that, a MVCC VFS is relatively straightforward. Here's an in-memory experiment if a few hundred lines of Go: https://github.com/ncruces/go-sqlite3/blob/v0.29.0/vfs/mvcc/...

I haven't settled on what's a good storage layer for something like this.

[phamilton]

Does that just do Database Level Conflict Checking?

[andersmurphy]

But for scale you don't want multiple writers. You want a single writer so that you can batch.