只要不手动删除这些数据，它们就会永远保留在性能数据库中。
Data remains in the performance database forever unless you delete it manually.
理解并正确使用RUNSTATS是维护高性能数据库的关键之一。
Understanding and properly using RUNSTATS is one of the keys to maintaining a high-performing database.
基于关系数据库建立了沥青路面使用性能数据库，采用图文格式建立了养护维修知识库；
Asphalt pavement performance database and rich text maintenance strategy information database are employed by reasoning mechanism.
要想禁止PerformanceExpert服务器收集数据，应该连接性能数据库，然后执行以下命令之一
To disable Performance Expert Server from collecting data, connect to the performance database and issue one of the following commands
如果使用长期历史，可以启动db2语句事件监视器来收集SQL事件监视器数据，并把收集的数据存储到PerformanceExpert服务器的性能数据库中。
If you use the long-term history, start a DB2 statement event monitor to collect SQL event monitor data and to store the collected data in the performance database of the performance Expert server.
那么您又该如何配置系统和数据库性能呢？
How do you then profile your system and database performance?
因此，这种方法的性能特性仅由目标数据库服务器决定。
Therefore, the performance characteristics of this approach are determined only by the target database server.
这将极大地提高性能，因为数据库节约了对相同的查询反复计算执行计划所需的所有开销。
This improves performance chiefly because the database saves all the overhead involved with calculating the execution plan for the same query over and over.
每个主日志的大小(页数量)对数据库性能有直接影响。
The size (number of pages) of each primary log has a direct bearing on database performance.
为了优化性能，每个活动数据库服务器任务应该有10MB内存。
For optimal performance, there should be 10mb of memory per active database server job.
另一个极大影响性能的配置参数是数据库缓冲池大小。
Another configuration parameter that dramatically affects performance is the database buffer pool size.
通过利用这些特性，可以改善数据管理效果，同时提供最优数据库性能。
By taking advantage of these features, you can manage data more effectively, while delivering optimum database performance.
本文的范围是数据库设计性能。
缓冲池竞争可以成为数据库性能中的重要因素。
Buffer pool contention can be a significant factor in database performance.
覆盖自由空间对数据库性能有负面影响。
Overwriting free space has an adverse affect on database performance.
为了提高应用程序的性能，数据库中的数据被缓存在应用服务器中。
To improve application performance, the data in the database is cached in the application server.
可通过在线搜索查找有关数据库性能的各种文章和书籍）。
Search online to find a vast number of articles and books dedicated to database performance.
然而，这种方式也会降低数据库性能。
基于数据库的复制的缺点是性能成本——数据库事务是昂贵的。
The downside of database-backed replication is the performance cost — database transactions are expensive.
总体数据库性能受到最繁忙的磁盘的带宽的限制。
Your overall database performance is limited by the bandwidth of your busiest disks.
但有时，您可能需要减小事务的作用域以获取吞吐量、改善性能并提高数据库的并发性。
However, there may be times when you need to reduce a transaction's scope to gain throughput, improve performance, and increase concurrency in the database.
对于使用比较静态的文件的数据库，性能改进可能不太显著。
For databases where the files used are static, the performance improvement may be less significant.
在显示内容块时不必调用加强性能的数据库。
No performance intensive database calls to display content pieces.
当连接数达到某一值后，数据库性能将开始下滑。
At a certain number of connections, database performance degrades.
消息选择的性能不及数据库sql选择，特别是在队列中有大量消息的时候。
Message selection does not perform as well as a database SQL selection, especially when the queue has a large number of messages.
考虑应用程序和数据库的性能特性的时机是在那些应用程序和数据库的初期设计阶段，也就是开发过程的开始阶段。
The time to consider the performance characteristics of applications and databases is during the initial design of those applications and databases, at the beginning of the development process.
测试性能：确保利用一个测试数据库来测试索引性能。
Test performance: Be sure to test the index performance with a test database.
为了确保最优的数据库性能，需要确保数据库得到了全部的优化。
To ensure optimal database performance, it is necessary to ensure that the database is fully optimized.
测试证明，并发用户对性能的影响在本质上与大型数据库对性能的影响存在很大的差异。
The nature of the performance impact of concurrent users proved to be quite different from that of large databases.
格式化新日志对于连接到数据库的应用程序是透明的，而且也不会影响数据库性能。
The formatting of new logs is transparent to applications connected to the database and does not impact database performance.
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