drop table if exists t1; SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE; CREATE TABLE t1(a int); SET TRANSACTION ISOLATION LEVEL READ COMMITTED; INSERT INTO t1 VALUES(1); INSERT INTO t1 VALUES(1); ERROR HY000: XEngine only supports READ COMMITTED and REPEATABLE READ isolation levels. Please change from current isolation level SERIALIZABLE SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; select * from t1; a 1 drop table t1;