该选项如果存在将禁止数据库锁定。
这通常用在当存在居间用户界面交互和数据库锁定不足的时候。
This is typically used when there is intervening user interface interaction and database locking in itself is not sufficient.
企业bean控制对后端数据的访问，并且在内部管理当前事务和数据库锁定。
The enterprise beans control access to the back-end data and internally manage the current transactions and database locking.
是什么使操作速度慢是数据库引擎需要创建和删除数据库锁定文件过于频繁的事实。
What makes operations slow is the fact that the database engine needs to create and delete the database lock file too often.
在保持数据完整性的同时，它们控制对后端数据的访问并在内部对当前事务和数据库锁定进行管理。
They control access to the back-end data and internally manage current transactions and database locking while preserving data integrity.
该选项如果存在将禁止数据库锁定。允许该选项可以在牺牲数据安全性的情况下提高性能。
This option, if present, disables database locking. Enabling this option may improve performance at the expense of data security.
但是，这种方法效率不高，无论是从编程时间还是从同时发生多个数据库锁定时数据库的利用率来说。
However, this is not efficient, either in programming time or in utilization of the database if multiple database locks could be held at one time.
对于获得最佳的应用程序性能，以及确保数据完整性和一致的应用程序行为来说，数据库锁定策略是非常重要的。
Database locking strategies are critical for gaining the best possible application performance, while ensuring data integrity and consistent application behavior.
当使用支持此功能的联合服务器时，需要对其数据库锁定策略进行仔细分析，以避免对源系统的性能造成负面影响。
When using federation servers that support this functionality, they need to be carefully analyzed on their database locking strategies to avoid negative impact to the performance of source systems.
其结果是：处理数据库锁定与同步的方案非常复杂，若不考虑数据库锁定与同步问题又会失去数据的完整性。
This often results in highly complex schemes to deal with database locking and concurrency, or alternatively, loss of data integrity when these issues are not considered.
你可以避免模式变化，准备在一个事务，但是请注意，您将需要使用BEGINIMMEDIATE可以肯定的是数据库锁定。
You can avoid schema changes by preparing inside a transaction, but note that you will need to use BEGIN IMMEDIATE to be sure the database is locked.
一开始我们的一家大型客户遇到一些问题，他们的基础设施的若干部分遇到锁定的问题，包括数据库。
Well, it started when a large customer of ours encountered some issues with other parts of their infrastructure that would lock up, including a database.
这种内存用于数据库级的任务，例如备份/恢复、锁定和SQL的执行。
This memory is used by database level tasks such as backup/restore, locking, and SQL executions.
锁定的另一个特例是需要锁定当前数据库行中不存在的项目。
Another special case of locking is the need to lock something where currently no database row exists.
正如前面提到的那样，EJB组件控制着对后台数据的访问，并管理着当前事务和数据库的内部锁定。
As mentioned previously, the EJB components control the access to the back-end data and manage the current transactions and database locking internally.
容器将用能被目标数据库接受的最低级锁定来装载数据。
The container will load the data with the weakest lock available for the targeted database.
这里使用了一种锁定机制，类似于数据库或者线程中的概念。
A locking mechanism, similar to concepts from database or threading comes into play here.
由于执行上的依赖，数据库中的锁定会影响到整个应用。
Due to execution dependencies, a lock-up in the database could impact the application.
为了实现这个目标，应该在锁定或关闭实例之后压缩数据库空间。
To achieve this, compress the database Spaces after the instance has been blocked out or shut down.
这将导致许多问题，如数据完整性、锁定策略以及数据库人员所熟知的一些问题。
That leads to many issues of data integrity, locking strategies, issues that are well known to database people.
可锁定的数据库对象有表空间、表和行，但是只有表和表空间可以显式地锁定。
Database objects that are lockable are table Spaces, tables and rows, however, only tables and table Spaces can be explicitly locked.
同乐观锁定策略相比，物理数据库锁需要持续较长的时间，因此应用程序性能和吞吐量很可能会受到影响。
As physical database locks are held for a longer time duration than with an optimistic locking strategy, there is more of a chance for performance and throughput being impacted.
EJB组件控制着对后台数据的访问，并管理着当前事务以及数据库的内部锁定。
The EJB components control the access to the back-end data and manage the current transactions and database locking internally.
在前面的示例中，两个用户交互之间将保持数据库游标打开，从而防止其他用户访问被锁定的数据段。
The previous example held the database cursor open between user interactions, preventing other users from accessing database segments that are locked.
我们期望确认当数据从数据库中取出时所有的行都已被锁定。
We want to make sure that all the rows are locked when the data is fetched from the database.
如果MD b以事务的方式锁定资源(例如，它可以锁定数据库行)，则在批结束之前，这些资源将保持锁定。
If the MDB locks resources transactionally (for example, it may lock a database row), these resources will not become unlocked until the end of the batch.
在这种情况下，锁定数据库记录有优点也有缺点。
Having the database records locked in this case is a good thing and a bad thing.
乐观的锁定，只当数据库发生更改时锁定记录。
Optimistic locking, where a record is locked only when changes are committed to the database.
在数据库中锁定数据有两个模型。
在数据库中锁定数据有两个模型。
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