The 2021 Cloud Report stands on benchmarks. Now in its third year, our report is more precise than ever, capturing an evaluation of Amazon Web Services (AWS), Microsoft Azure (Azure), and Google Cloud Platform (GCP) that tells realistic and universal performance stories on behalf of mission-critical OLTP applications.

John Kendall

January 15, 2021

We didn’t implement SELECT FOR UPDATE to ensure consistency. Unlike Amazon Aurora, CockroachDB already guarantees serializable isolation, the highest isolation level provided by the ANSI SQL standard. Contention happens. And application developers shouldn’t need to risk the integrity of their data when transactions contend. To combat this, CockroachDB must occasionally return errors prompting applications to retry transactions that would risk anomalies, such as write skews. This means that just like with PostgreSQL in serializable isolation, developers need to implement retry-loops for contended transactions. For developers accustomed to relational databases with lower isolation levels, this can be an unfamiliar pattern.

John Kendall

June 22, 2020