The DB2 optimizer is a highly sophisticated cost-based optimizer.
DB 2优化器是一款高度复杂的基于成本的优化器。
Only statistics stored in the dictionary itself have an impact on the cost-based optimizer.
只有存储在字典视图中的统计信息，才会被优化器使用。
This set is input to the cost-based optimizer that decides whether to use any of the eligible indexes or not.
将该组索引输入到基于成本的优化器，这个优化器决定是否使用任何合适的索引。
This algebra is exploited by a cost-based optimizer that can freely mix regular and compression-aware operators.
该代数由基于成本的优化器使用，该优化器能够自由混合使用常规运算符以及与压缩有关的运算符。
WebSphere Federation Server USES its cost based optimizer in order to determine the optimal access path to retrieve and process the data.
WebSphereFederationServer使用它的基于成本的优化器，确定检索和处理数据的最佳路径。
IBM does not publish the actual, in-depth details of how the optimizer determines the best access path, but the optimizer is a cost-based optimizer.
IBM并没有发布优化器如何确定最佳存取路径的真正和深入的详细信息，但优化器是一个基于成本的优化器。
A sliding mode based optimizer and traction control system which is used for a traction control system of in-wheel driven ev is developed in this paper.
改进了用于轮式驱动电动车牵引控制中最优滑移率辨识的滑模变结构优化器，设计了基于滑模变结构的牵引控制系统。
One of the distinguishing features of Federation Server is that it uses the powerful technology of DB2's cost-based optimizer to find the best access path for federated queries.
FederationServer的一个独特的特性是，它使用DB2强大的基于成本的优化器技术来发现联邦查询的最佳访问路径。
However, in the absence of data distribution information, the optimizer will calculate selectivity for filters of different types based on table indexes.
然而在缺乏数据分布信息的情况下，优化器将基于表索引计算不同类型筛选器的选择性。
When this attribute is not specified, the optimizer makes a cost-based decision to select an access plan for the given table.
如果未指定该属性，优化器将生成一个基于成本的决策，为给定的表选择一种访问计划。
The optimizer considers star join optimization when appropriate and decides on star join plan based on cost considerations in order to come up with best execution plan for a star join query.
为了实现星型连接查询的最佳执行计划，优化器在适当的时候会考虑星型连接优化，并根据成本因素来决定星型连接计划。
When you use the actual value in the query, the optimizer will be able to calculate the estimation based on the real value.
如果您在查询中使用实际值，那么优化器将能够基于真实值来计算评估值。
As you've seen in the steps above, the optimizer selects the optimal access plan based on available statistics.
您可以从以上步骤看到，这个优化器基于可用的统计信息选择了最优的存取计划。
The optimizer will return the best plan using a cost-based decision.
优化器将通过基于成本的决策返回最佳计划。
The optimizer performs complex calculations based on a host of information.
优化器根据许多信息执行复杂的计算。
The optimizer picks additional indexes for the IXAND plan in a cost-based fashion.
优化器将以一种基于成本的方式为IXAND计划挑选额外的索引。
This now populates the explain tables with the access plan chosen by the optimizer based on real and virtual indexes.
现在将用优化器根据实际和虚拟索引选择的访问计划来填充解释表。
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.
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。
Accurate index information and statistics are fundamental to cost-based decisions in the query optimizer.
准确的索引信息和统计信息是查询优化器中基于成本的决策的基础。
However, you would still like the optimizer to find the best access plan based on the values that users have passed into the query.
然而，您可能仍然希望优化器基于用户传递给查询的值来查找最佳的存取计划。
The optimizer ACTS based on statistical data about the number of rows in a table, the use of space by a table or index, and other information.
优化器的操作基于数据表中的行数、数据表或索引使用的空间以及其他信息的相关统计数据。
If current statistics are not available, the optimizer may choose an inefficient access plan based on inaccurate default statistics.
如果无法获得当前的统计数据，优化器就可能会基于不准确的默认统计数据选择低效的访问计划。
The optimizer may add more indexes to the IXAND plan in a cost-based fashion.
优化器可能会以一种基于成本的方式将更多索引加入到 IXAND计划中。
The optimizer calculates its cardinality estimate — that is, the estimated number of rows returned by the query — based on the statistics available.
优化器根据可用的统计信息计算基数的估计值，即预计查询返回的行数。
DB2 UDB comes with a powerful cost-based query optimizer that determines the best strategy to access data.
DB 2 UDb中包含了一个功能强大基于成本的查询优化器，用于确定访问数据的最佳策略。
The optimizer chooses between the two access methods using a cost-based analysis.
优化器将通过基于成本的分析来在这两个访问方法之间进行选择。
The optimizer will deduce key value selection based on the functional dependency of the column within the row.
优化器将根据行中列的函数依赖性来推断关键值选择。
The optimizer will add more indexes to the IXAND based on cost.
优化器将根据成本向IXAND添加更多索引。
The optimizer compares the cost of each candidate access path based on the information from multiple inputs, for example, see the following.
优化器根据多个输入的信息来对比候选访问路径的成本，如下例所示。
Use the -fd option, which would generate the db2fopt commands required to tell the optimizer to use the specified size rather than calculating based on the buffer pools available for this database.
使用将生成必要的db 2 fopt命令的- fd选项来告诉优化器使用指定大小，而非基于对该数据库可用的缓冲池进行计算。
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