CockroachDB’s Consistency Model
But, of course, we also want our database to be resilient to machine failure, and we want the transactions to execute fast, and we want many transactions to execute at the same time, and we want data for European customers to be served from European servers and not cross an ocean network link. And yet, it is allowed by the Serializable isolation level and, in fact, likely to occur in many distributed databases (spoiler alert: not in CRDB), assuming the actors were quick to yell at each other and run their transactions. While database people were concerned with transaction isolation, researchers in distributed and parallel systems were concerned with the effects of having multiple copies of data on the system’s operations.
Source: www.cockroachlabs.com