The best part of moving to PostgreSQL is that it is sort of the defacto standard wire protocol for relational databases now and that enables you to "grow into" something like CockroachDB down the line when you need that sort of scale.
Can you explain your comment in more detail as I am not really sure what you getting at with "the defacto standard wire protocol for relational databases" nor "grow into" something like CockroachDB".
In the case of CockroachDB (a distributed database), it has the same wire-level protocol as Postgresql. So if your programming language has a Postgresql driver (and it likely does), then you can also talk to a CDB database as well.
The SQL dialects are not the same, though they are similar, so you will have to go through your code to see if you need to fix anything. Moving the data itself over is fairly straight-forward:
Not parent. No idea about the defacto standard comment. CockroachDB client protocol is* compatible with PostgreSQL. Edit: as well as SQL syntax, that's the important bit.
Meaning you could in theory mirror data to CockroachDB and the point your clients to it instead of PostgreSQL. CockroachDB is aiming to solve horizontal scaling, hence the "grow" comment.
