下面给出了更新统计信息的两种方法——不删除依赖于昵称的对象。
Two ways to update statistics — without dropping of objects dependent on the nickname — are outlined below.
在我们对基准的第一个改进中，我们向账单表增加索引，并为表更新统计信息。
In our first improvement to the benchmark, let us add an index on the bills table and update statistics for the table.
重建将自动重建所有索引列统计信息，而重新组织根本不会更新统计信息。
REBUILD will automatically rebuild all index-column statistics, whereas REORGANIZE won't update statistics at all.
这些可更新的视图允许更新某些统计信息，从而研究假想数据库的性能，或者更新统计信息而不使用RUNSTATS实用程序。
These updatable views allow you to update certain statistical information to investigate the performance of a hypothetical database, or to update statistics without using the RUNSTATS utility.
其目标是允许DB2确定工作负载需要哪些统计信息，并定期在后台自动运行RUNSTATS实用程序，以便按需更新统计信息。
The objective is to allow DB2 to determine which statistics are required by the workload, and automatically run the RUNSTATS utility in the background periodically to update statistics as needed.
RUNSTATS实用程序用于更新系统目录表中的统计信息，以帮助查询优化过程。
The RUNSTATS utility updates statistics in the system catalog tables to help with the query optimization process.
我们可以使用RUNSTATS命令来进一步更新这些统计信息，然后使用得到的最新访问计划来重新尝试这个应用。
Further action can be taken to update the statistics using the RUNSTATS command, then retrying the application with an up-to-date access plan in place.
目录统计信息的更新将为优化器提供最新的地图，以便在整个地形中快速定位。
Updating the catalog statistics would provide the optimizer with the most current map to navigate quickly through the terrain.
DB 2判断需要哪些统计信息以及哪些需要更新，然后在后台自动地运行RUNSTATS实用程序。
DB2 determines which statistics are required and need to be updated and then automatically executes the RUNSTATS utility in the background.
这意味着您应该在创建索引之前加载数据，或者在加载数据之后更新表的统计信息。
This means that you should either load your data prior to creating your index or update the statistics on your table after your data is loaded.
数据库服务器不更新系统编目表中的统计信息。
The database server does not update the statistics in the system catalog tables.
更新步骤4中创建的行，记录步骤5中收集的统计信息和完成步骤5所花费的时间。
Update the row created in step 4, and record the statistics gathered in step 5 and the time to complete step 5.
即使表的行数保持一致，使用由RUNSTATS更新的统计信息来更改数据内容可以产生不同的、也许更好的访问路径。
Even if the number of rows in a table remains consistent, changes in data contents can result in different, and hopefully better, access paths using statistics updated by RUNSTATS.
从上面的例子中可以看到，该过程运行得很好，并导致给定表的统计信息得到更新。
As you can see from the above examples, the procedure is working quite well and causes the statistics for the given tables to be updated.
建议在手动更新任何统计信息之前，先调用RUNSTATS命令，以便起始点能够准确地反映当前状态。
It is recommended that you invoke the RUNSTATS command before manually updating any statistics, so that your starting point accurately reflects the current state.
DB 2定期检查已经更新其统计信息的表和索引，判断它们是否需要重组，当需要时安排执行这些操作。
DB2 determines if a table or index reorganization by periodically checking tables and indexes that have had their statistics updated, and schedules such operations whenever they are necessary.
例如，它周期性地自动执行RUNSTATS实用程序，以更新关于表及相关索引的物理特征的统计信息。
For example, it automatically executes the RUNSTATS utility on a periodic basis to update statistics about the physical characteristics of a table and the associated indexes.
可以使用runstats实用程序来更新系统编目表中的统计信息，使查询优化过程更容易一些。
The runstats utility can be used to update statistics in system catalog tables to facilitate the query optimization process.
Design Advisor生成的输出文件包含一组ddl语句，用于创建MQT、刷新和更新MQT上的统计信息，以及在其上创建索引。
The output file generated by the Design Advisor contains a set of DDL statements that create MQTs, refresh and update statistics on the MQTs, and create indexes on them.
下列REORGCHK命令检查是否需要REORG，并且更新关于表bench .customer的统计信息。
The following REORGCHK command examines whether the REORG is required and also updates the statistics on table bench.customer.
对缓存利用率、更新和查询的全面统计信息。
Comprehensive statistics on cache utilization, updates, and queries.
ControlCenter的昵称统计信息更新程序的一些更灵活的选项还提供了新功能，即NNSTAT。
The new functionality is also available through more flexible options in Control Center's nickname statistics update facility, which calls NNSTAT. NNSTAT can collect statistics in one of two modes.
如果有一个昵称，它的统计信息需要更新，以反映在其数据源上新出现的远程统计信息，那么您可能会忍不住删除和重新创建该昵称。
If you have a nickname whose statistics need to be updated to reflect the new remote statistics on its data source, you might be tempted to drop and recreate the nickname.
每个基类负责跟踪某项操作前后的性能，还需要更新系统范围内这条信息的性能统计值。
Each base class is responsible for tracking performance before and after certain operations and will need to update system-wide performance statistics for that information.
更新目录统计信息，这部分强调收集和维护最新数据库统计信息的重要性，缺少这项工作常常是导致许多性能问题的源头所在。
Updating catalog statistics, which emphasizes the importance of collecting and maintaining up-to-date database statistics, the lack of which is often the source of many of the performance problems.
如果为一个昵称收集了统计信息，那么在数据源上对相应远程表的远程统计信息进行更新时，这些统计信息不会自动更新。
Once the statistics are gathered for a nickname, they are not automatically modified when the remote statistics are updated on the data source for the corresponding remote table.
事实上，如果我们看一下基准代码，我们就会发现，该表已被创建、填充、并使用，但是统计信息没有被更新。
In fact, if we go look at the benchmark code, we will see that the table is created, populated, and used, but statistics are never updated.
DB 2优化器使用目录统计信息来确定最佳的访问路径，而更新这些目录统计信息所采用的主要方法就是运行RUNSTATS实用程序。
The DB2 optimizer USES catalog statistics to determine the best access path, and the main method employed to update these catalog statistics is to run the RUNSTATS utility.
但由于更新患者姓名的频率远远低于更新患者统计信息的频率，因此就性能来说，系统依然得到了优化。
But, since you don't update a patient name as often as you access demographics, you've still optimized the system for performance.
但由于更新患者姓名的频率远远低于更新患者统计信息的频率，因此就性能来说，系统依然得到了优化。
But, since you don't update a patient name as often as you access demographics, you've still optimized the system for performance.
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