Both Cockroach and CedarDB didn't rewrite anything, they built stuff from scratch. Just used the same client protocol. There are a bunch of other unrelated databases using Postgres protocol btw.
I'm not talking about speaking the protocol. I'm talking about trying as hard as they can to be as indistinguishable from Postgres (to a non-operations user) as they can. And that list is very small.
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Both Cockroach and CedarDB didn't rewrite anything, they built stuff from scratch. Just used the same client protocol. There are a bunch of other unrelated databases using Postgres protocol btw.
I'm not talking about speaking the protocol. I'm talking about trying as hard as they can to be as indistinguishable from Postgres (to a non-operations user) as they can. And that list is very small.