Does the CAP theorem imply that ACID is not possible for distributed databases?

Question

There are NoSQL ACID (distributed) databases, despite CAP theorem. How this is possible? What\'s the relation between CAP theorem and (possible/not possible of) being ACID?

Answer 1

The PACELC theorem extends CAP to talk about the tradeoffs even when partitions aren't happening. One of the exciting insights for distributed systems, is that they can be made partition tolerant without losing consistency, when consensus protocols such as RAFT or Paxos are used to create a transaction log. The Calvin protocol combines a RAFT log with deterministic transaction application.

FaunaDB implements Calvin, allowing it to maintain ACID transactions with strict-serializability, even during partitions or during replica failure, as long as a quorum of replicas is not partitioned.