First, the propagation properties of transactions
1, propagation: used to set the transaction propagation behavior, a way to run an open transaction when the method, the current approach is to use the original transaction or open a new business.
(1) propagation.REQUIRED: default value, use the original transaction.
(2) Propagation.REQUIREDS_NEW: the original transaction suspension, open a new transaction
Second, the transaction isolation level
1, uncommitted read: READ UNCOMMITTED transaction allows a transaction to read uncommitted changes 2
2. Read Committed: READ COMMITTED require a transaction can only read 1 2 modify transaction has been submitted
3, repeatable read: REPEATABLE READ transaction to ensure a plurality of times can be read from a field to the same value, i.e., prevent other transactions during an execution of the transaction to update the field
4, serialization: SERIALIZABLE ensure that the transaction 1 can be read many times from one table to the same line, during a transaction execution 1, prohibits other transactions on the table to add, update and delete operations. To avoid any concurrency issues, but the performance is very low.
ioslation: to set the transaction isolation level
Isolation.REPEATABLE_READ Repeatable read (MySQL default transaction isolation level)
Isolation.READ_COMMITTED Read Committed (Oracle default transaction isolation level, the development of commonly used isolation level)