为了解决以“大集中”方式设计的企业管理系统的查询性能下降的问题，提出了完善的查询性能优化模型。
In order to solve query performance degradation problems of the enterprise management system designed by "big focus" approach, and propose a sound query performance optimization model.
因此，如果统计数据不准确或者过期，或者冲突，优化器会对查询计划中各步骤的成本评估不准确，从而导致糟糕的性能。
Consequently, if the statistics are inaccurate, outdated, or conflicting, the optimizer will create inaccurate estimates for the costs of the steps in a query plan, leading to poor performance.
衡量系统的性能，以及测试您的实体不满足预期结果的地方，尝试调整容器以优化查询。
Measure the performance of the system, and where your entities do not meet expectations, try and tune the container to optimize the queries.
任务包括计划并管理数据库、调优性能与容量、创建和维护索引并优化查询、监测、以及管理备份与恢复。
Tasks include planning and administering the database, tuning for performance and capacity, creating and maintaining indexes and optimizing queries, monitoring, and managing backup and recovery.
xml索引、查询优化、存储管理和其他DB 2服务有助于确保出色的效率和运行时性能。
XML indexing, query optimization, storage management, and other DB2 services help ensure efficiency and strong runtime performance.
当查询性能中出现例外情况时，优化指南和统计视图特性对于弥补访问计划估计的不准确性非常有用。
Optimization guidelines and statistical views are useful features to compensate the access plan evaluations when exceptions in query performance occur.
处理程序api的使用完全集成在捕捉和查询组件中，并通过优化数据库存储和查询，显著改进系统的性能。
The use of the handler API is completely integrated into the capture and query component, and it greatly improves the performance of a system by optimizing database storage and retrieval.
开发人员必须编写代码来实现数据访问层，包括优化SQL查询、缓存结果以优化性能，而不会损害应用程序的规模。
Developers must write code to implement the data access layer, including optimizing SQL queries, caching results to optimize performance, without compromising an application's footprint.
最后，您将了解如何对查询进行分析以优化数据库的性能。
Finally, you'll see how you can profile your queries to optimize the performance of your database.
这是IBM进行数据库查询来提高性能的优化努力的结果。
This is a result of the optimization efforts IBM performed to improve the performance of database queries.
Informix 11.7中的优化可以显著提高查询和事务性能，已经将物理更改运用到POWER 7平台，尽可能实现透明改进。
Optimizations in Informix 11.7 have dramatically improved query and transaction performance, and have leveraged physical changes to the POWER7 platform to make transparent improvement possible.
在Entity框架中优化查询性能时，应该针对特定的编程场景做出最佳选择。
When optimizing query performance in the Entity Framework, you should consider what works best for your particular programming scenario. Here are a few key takeaways.
该信息允许快速识别模型和查询优化，应用该优化的目的是达到更好的性能。
This information permits the rapid identification of model and query optimizations which could be applied in order to achieve better performance.
查询优化器可能得出一个不同的查询执行计划，这个计划可以专门为最快地获取前'N '行，而不是所有结果行提供良好的性能。
The query optimizer might come up with a different query execution plan tailored to provide good performance for fast retrieval of first 'n' rows rather than all the result rows.
DB 2优化器使用这些统计信息为任何给定的查询决定最有效的访问计划，从而提高查询的性能。
The DB2 optimizer USES these statistics to determine the most efficient access plan for any given query, which improves query performance.
经过优化的性能：为联邦系统开发的应用程序有能力实现出色的性能，而且不需要实现特殊战略来评估查询。
Optimized performance - the power of applications developed for the federated system to achieve strong performance without the need to implement special strategies to evaluate the queries.
通过这个编辑器，您也能够访问可以协助分析和优化SQL查询性能的IBM工具。
Through the editor, you can also access IBM tools that help you analyze and tune the performance of your SQL queries.
要改进性能，联合需要经常使用缓存、物理查询表(MQT)以及分布式查询优化和执行。
To improve performance, federation frequently USES caching, materialized query tables (MQTs), and distributed query optimization and execution.
我们考虑物化查询表(MQT)支持一个重要的选项来进一步优化联邦服务器的性能。
We consider materialized query table (MQT) support an important option to further fine tune the performance of your federated server.
然而需要注意的是，先进的优化器在生成一个特定的访问计划时，必然有其原因，所以在应用指南之前，务必理解是什么原因导致查询的性能低下。
However, note that the state-of-the-art optimizer has a reason to generate a particular access plan, so it is important to ensure that we understand the inefficiency before we apply the guidelines.
另一个用途是当DB 2查询优化器确定只需检查分区的一个子集来回答特定查询时，基于分区消除以提高性能。
Another purpose is to improve performance based on partition elimination when the DB2 query optimizer determines that only a subset of the partitions need to be examined to answer as particular query.
有时候客户报告的性能问题中说某个特定查询的执行没有优化。
Sometimes customers report a performance problem where a specific query is not performing optimally.
参数化查询的主要性能好处是优化器可以制定在重复执行语句时能够再使用的存取路径。
The key performance benefit of parameterized queries is that the optimizer can formulate an access path that can be reused over repeated executions of the statement.
编辑器的工具栏包含了一些可用于运行脚本、导入和导出sql语句及使用分析和优化脚本查询性能的按钮。
The editor toolbar contains buttons that you can use to run your script, to import and export SQL statements, and to access tools for analyzing and tuning the performance of queries in your script.
而且，Hibernate将此设置用作针对某些数据库类型的数据库提示从而优化查询性能。
Moreover, Hibernate USES this setting as a database hint against certain database types for optimized query performance.
那些熟悉systemi和数据库查询性能分析和调优的人就会理解控制优化目标是优化性能的关键步骤。
Those familiar with System I and database query performance analysis and tuning, understand that controlling the optimization goal is a critical step to optimizing performance.
VisualExplain工具提供了一个sql语句的图形化视图，这样您可以分析您的查询和优化它们的性能。
The Visual Explain tool provides a graphic view of your SQL statements so that you can analyze your queries and tune them for better performance.
如何重新组织表来优化查询性能。
在DB 2中，性能优化主要针对大型数据库，如SAPBusinessInformationWarehouse (BIW)；而SQL优化的目标则是为了缩短查询时间。
In DB2, performance optimization is targeted to large databases, such as SAP Business Information Warehouse (BIW), while SQL optimization aims to improve query times.
优化的性能：为联邦系统开发的应用程序可以取得强大的性能，并且不需要实施特殊的策略来计算查询。
Optimized performance: the power of applications developed for the federated system to achieve strong performance without the need to implement special strategies to evaluate the queries.
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