- YugabyteDB is currently on Postgres 11.2 with plans to keep upgrading.
- Cockroach is not pinned to any Postgres version so its compatibility is reliant on their implementation. Not a bad thing, just different than YB.
- Like you said Timescale is in lockstep with latest Postgres (14 at the time of this comment) https://blog.timescale.com/blog/massive-scale-for-time-serie...
- Materialize is not really focused on scaling because that is not really what it is for, https://materialize.com/blog-roadmap/
- I might consider moving Spanner to the Somewhat compatible category. Lack of stored procedures and triggers makes it not a drop in replacement for those moving from Oracle/MS SQL https://cloud.google.com/spanner/docs/reference/postgresql/o...
- For native Postgres scaling strategies, we could call attention to Crunchy Data or Percona
Very nice to lay this out and I pretty much agree with the labels and categories on here. I would be you will get some people reaching out since Postgres compatibility is something these vendors compete on.