Active-active is when you don't have any replicas, you have just one data store and multiple 'engines' accessing it. So there is no replication, because there is nothing to replicate. So CockroachDB is definitively not active-active, despite their claims to the otherwise; what they call active-active is two-way synchronous replication, which is worse than asynchronous replication because of the latency and worse than Oracle RAC active-active because it's less fail-tolerant. In Oracle RAC your cluster is up and running even if just one engine is still alive, in CockroachDB approach when you lose majority of nodes the cluster goes down. Obviously Oracle RAC active-active has it's own downsides, too, but it's another topic. EDIT to expand: Think about a SQL transaction. In Oracle RAC it gets picked up by any of the nodes and is executed by this node. All the other nodes see updated data immediately. In CockroachDB the same transaction would need to be executed by each of the nodes separately plus the overhead of communication between the nodes.