Transaction management in spring (3)
transaction isolation level
In theory, transactions should be completely isolated from each other to avoid problems caused by concurrent transactions. However, that would have a huge performance impact since transactions must run sequentially.
In actual development, in order to improve performance, transactions will run at a lower isolation level.
The isolation level of a transaction can be specified through the isolation transaction property
Transaction isolation levels supported by Spring
The isolation level of transactions is supported by the underlying database engine, not by the application or framework.
Two transaction isolation levels supported by Oracle: READ_COMMITED, SERIALIZABLE
Mysql supports 4 transaction isolation levels.
Set isolated transaction properties
When managing transactions declaratively with the @Transactional annotation, you can set the isolation level in the isolation attribute of @Transactional.
In transaction notifications, the isolation level can be specified in the <tx:method> element
Set the rollback transaction property
By default only unchecked exceptions (RuntimeException and Error type exceptions) will cause transaction rollback. Checked exceptions do not.
The rollback rules of a transaction can be defined by the rollbackFor and noRollbackFor attributes of the @Transactional annotation. These two attributes are declared as Class[] types, so multiple exception classes can be specified for these two attributes.
rollbackFor: must rollback when encountered
noRollbackFor: A set of exception classes that must not be rolled back when encountered
In transaction notifications, rollback rules can be specified in the <tx:method> element. If there are more than one exceptions, separate them with commas.
