Oracle rollback notes

Oracle rollback notes savepoint a1; -- set a storage Point a1; update tmp set username = 'zhangsan' where userid = '000000' -- modify a data savepoint a2; -- set a storage Point a1; update tmp set username = 'lily' where userid = '000000' -- modify a data rollback to a2; -- roll back to the storage point a2. All data modifications after the a2 save point are considered invalid. Rollback to a1; -- here, You can refresh from the a2 save point to the a1 save point. In this case, all data modifications after the a1 save point are considered invalid. Rollback; -- roll back all. That is, all data modifications after the transaction is committed are revoked. Commit; -- commit the transaction to commit the rolled back transaction and delete all save points. Note: We can roll back from a2 to a1, but not from a1 to a2. That is to say, you can only roll back from the previous point!