摘要：
Table Lock ModesThese table lock modes are automatically assigned by the Oracle server:Row Exclusive(RX):INSERT,UPDATE,DELETERow Share(RS):SELECT ... FOR UPDATEManually Locking a TableManually acquired in LOCK TABLE StatementSQL>LOCK TABLE HR.employees IN share MODE;Share(S)No DML operations allo 阅读全文
摘要：
DML LocksA DML transaction gets at least two blocks:A shared table lockAn exclusive row lockA shared table lock主要是阻止DDL语句对当前表进行修改.An exclusive row lock主要是阻止别的transaction修改同一条记录.如何查看锁的信息?有三个重要的动态性能视图:v$transaction:记录了当前活动的transaction.desc v$transactionSQL> desc v$transaction; Name ... 阅读全文
摘要：
ObjectivesAfter completing this lesson,you should be able to do the following:Define levels of lockingIdentify causes of contentionPrevent locking problemsUse Oracle utilities to detect lock contentionResolve contention in an emergencyResovle deadlock conditionsModes of LockingOracle Database uses t 阅读全文