[jaytaylor]

  > If you build a custom database 
  > engine that fundamentally stores
  > everything as key-value, and then
  > builds relational abstractions on
  > top

Sounds like this could be FoundationDB, among other contenders like TiDB.

https://foundationdb.org

[thu2111]

More like myRocks. FoundationDB doesn't use LSM and definitely wants to do lots of overwriting in place. TiDB uses Rocksdb and would be closer.