Interesting. I've been thinking about it as well. I wrote some code to prototype it here: https://github.com/pgdogdev/pgdog/blob/main/pgdog/src/backen...

We used it to shard a database at Instacart after your time instead of the “replicate everything and drop the data on the shard approach”. That combined with dropping all the indexes (minus the primary key) worked well for the data copy/initial sharding.

That's good to know. Don't hesitate to reach out if you ever want to chat about this stuff. My email: [email protected]