We collaborated with YugaByte to validate YugaByte DB at version 1.3.1’s beta support for serializable SQL transactions. We found two safety issues: a race condition allowing DEFAULT columns to be initialized to NULL, and a serializability violation (G2-item) associated with tablet servers losing their connection to master nodes. We also found several problems with DDL statements like table creation, and some availability issues, such as slow recovery during network partitions, and process leaks. YugaByte has addressed the G2 issue as well as some of the other bugs, and is working on remaining issues.