pessimistic locking

Certain critical updates should always be done with pessimistic locking.

进行特定的关键性更新时，应始终使用悲观锁定方式。

Fixed FOR UPDATE statements not generated for pessimistic locking

修复了不会生成悲观锁定的FOR UPDATE语句

Optimistic and pessimistic record locking

乐观以及悲观的记录锁定

For more information, see Optimistic and pessimistic record locking in the Information Center.

您可以在Information Center中的乐观和悲观记录锁机制，查看更多信息。

For instance, if the application uses pessimistic locking, don't change the application during the migration to use optimistic locking.

例如，如果应用程序使用悲观锁定，则在迁移过程中不要将应用程序更改为使用乐观锁定。

The main problem with a pessimistic locking approach is that transactions have to wait for each other.

悲观锁定方法的主要问题是事务之间必须互相等待。

A pessimistic locking strategy assumes that the probability is high that another user will try to modify the same row in a table that you are changing.

悲观锁定策略的前提是，另一个用户很可能试图修改您正在修改的某个表行。

Of course this also leads to the same issues such as questions about optimistic versus pessimistic locking, lock granularity, and the performance impact.

然而这也带来了和数据库事务同样的问题，比如乐观锁还是悲观锁，锁的粒度以及对性能的影响。

However, that "no" comes with this caveat: If you use a CM solution that effectively supports a pessimistic locking scheme, then physical partitioning can be a way to avoid merges.

然而，这个“不可以”中也包括如下这层含义：如果您使用一个能够有效地支持锁定安排的CM解决方案的话，那么物理划分就能够作为避免合并的一种手段。

The updating transaction may in theory use optimistic or pessimistic transaction locking at the time of update.

在理论上，更新事务可以使用乐观或悲观锁定进行更新。

The advantage of pessimistic locking is that it is guaranteed that changes are made consistently and safely.

悲观锁定的优点就是能够保证实现一致且安全的更改。

Pessimistic locking, where a record is locked while it is edited.

悲观的锁定，在编辑记录时将其锁定。

Pessimistic record locking, which provides a way to prevent situations where multiple users can edit a record at the same time

消极记录锁定，它提供了避免发生多个用户同时编辑一条记录情况的手段

However, this should be evaluated on a case by case basis& there are situations where pessimistic locking is necessary.

但是，在实际使用中应根据具体情况进行分析，有时也需要悲观锁定方案。

These strategies involve checking the time-stamp of each operation and determining the correct order for scheduling, as well as when/ how records are locked ( e.g., optimistic vs. pessimistic locking).

这些策略包括检查每个操作的时间戳及为进度确定的正确顺序，以及什么时候或如何锁定记录（举例来说，乐观的vs悲观的加锁）。

However, for entity beans this rule has to be relaxed; due to the nature of the model, most pessimistic locking access intents require at least Repeatable Read.

但是，对于实体Bean则可不遵循此规则，由于该模型本身的特性，多数悲观锁定访问都需要至少Repeatable Read。

WebSphere XS pessimistic locking is used during each action, and control is returned to the user only after that action has been committed to the primary and replica versions of the data.

WebSphere XS悲观锁会在每次操作期间使用，控制权仅在操作提交到数据的主要和副本版本后才返还给用户。

Avoid Pessimistic Locking since the pessimistic locks affect the throughput and it's difficult to recover from bad locks.

应当尽量避免使用悲观锁，因为它会影响吞吐量，而且很难从坏锁（bad locks）中恢复。

Developers can use pessimistic locking but they will need to define the lock manager using EntityManager's lock() or find() methods.

当然，开发者也可以自行使用悲观锁（pessimistic locking），但他们需要使用EntityManager的lock（）或者find（）方法来定义锁管理器。

As for the concurrent control techniques the prototype system implements the method of pessimistic locking with accordance to the features of the graphic objects that CAD systems operate on.

其三，根据CAD系统处理的图形对象的特点，原型系统实施了悲观加锁的并发控制技术。