This can lead to a sub-optimal plan compared with one selected when the SQL includes the exact values.
这相对于在SQL包含确切值的查询而言得到的值是次优化的。
Those models can be references of choosing optimal plan of design about energy efficient residential buildings.
分析模型可供节能住宅设计方案优选时参考。
The optimizer relies on statistics to properly cost alternative query execution plans (QEPs) and choose the most optimal plan.
优化器是依靠统计信息来计算可选查询执行计划（QEP）的开销，同时选择出最优的计划。
The results show that the problem of selecting the optimal plan in multi-target orthogonal test design can be solved very well.
结果表明方法能够很好地解决多指标正交试验设计中最优方案的选择问题。
A query plan ideally is an optimal plan to execute the given query - that is, it determines the most efficient way to fetch the data.
理想情况下，查询计划是执行给定查询的最佳计划—也就是说，它会确定抓取数据的最佳方式。
The method can also be adopted in other areas and various engineering projects as well as the optimal plan management of industrial enterprises.
指出该方法也适用于其它各类工作、工程项目以及对工矿企业实施优化的计划管理。
The many complex factors and the dynamic nature of data means that an optimal plan evaluation is often a complex process indeed for any database system.
这么多复杂的因素，再加上数据本身的动态性，使得最佳计划的评估对于任何数据库系统而言通常都是一个复杂的过程。
So, the accuracy of getting an optimal plan is entirely dependant on the up-to-date statistical information about the database objects involved in the query.
因此，获得最佳计划的准确性完全取决于关于查询中所涉及的数据库对象的最新统计信息。
The test shows that the optimal plan worked out by the method presented here has been proved far superior economically to that by the conventional method.
经实践检验，用所提方法制定的优化调度方案较常规方案更具有明显的经济效果。
The 2007 Guideline of European Hypertension Prevents and Controls recommends that one of the optimal plan of blood lowering is uniting the ACEI treatment.
2007年欧洲高血压防治指南推荐的优选降压方案之一是联合acei治疗。
The model first generates judge-array based on fuzzy optimal theory; and latter determines the optimal plan with the entropy weight decision-making method.
该模型首先根据模糊优选理论生成判断矩阵，后用熵权决策法确定优选方案。
The setting principle of bureau data and optimal plan in telecommunication network are introduced, based on the operating condition of SPC and the network problems.
针对广铁程控交换机的现状和网络存在的问题，提出局数据的设置原则和网络优化方案。
For single operating parameter units, secant method coupled with a unit simulator is used to search feasible operating conditions implementing the quasi-optimal plan.
对于单操作参数装置，利用正割法搜索实现拟最优计划的可行操作条件。
Finally the activity of VE is to summarize and evaluate the situation of the optimal plan, including economic benefit evaluation of enterprise and social effect evaluation.
价值工程活动的最后是对优选方案实施的情况进行总结评价，包括企业经济效益评价和社会效果评价。
With this model, an optimal plan for monthly local allocation and transportation of grain can be compiled on a microcomputer, and its economic efficiency is quite remarkable.
运用该模型可以在微型计算机上确定区域月粮食最优调运计划，经济效益十分显著。
Clearly the body plan of Schizodactylus is not merely good, but optimal, at least for the environment the animal lives in.
显然，节肢动物的体型方案不仅是最好的，也是最佳的，至少对这种动物生活的环境而言是如此。
You can leverage the extended use of multi-column statistics in DB2 9.5 to provide the optimizer more information to better estimate the cardinality in order to choose an optimal query access plan.
您可以利用DB2 9.5 中的多列统计信息的扩展用途来为优化器提供更多的信息，从而使优化器更好地估计基数，选择最佳的查询访问计划。
In this case, the optimizer creates a different access plan, which may not be optimal if the user input is 0.
在这种情况下，优化器会创建的存取计划都是不一样的，这在用户输入为0时可能不是最优的。
Both statistical views and REOPT allow the optimizer to compute a more accurate cardinality estimate and consequently choose an optimal query execution plan.
统计视图和REOPT都使优化器可以计算出更精确的基数估计，而后选择一个最佳查询执行计划。
Ideally, the database chooses the most "optimal" access plan — that is, the plan that returns the data most efficiently and quickly.
在理想情况下，数据库会选择最“优化”的访问计划——也就是最高效最快地返回数据的计划。
This brings little overhead for compiling, but gives an optimal access plan.
这会增加一些编译负载，但却能够产生一个最优的存取计划。
If the cost estimatd does not correctly describe the real cost during SQL execution, the access plan picked by the optimizer may not be optimal.
如果评估得到的开销不能够正确反映SQL执行中的实际开销，那么优化器所选择的存取计划可能不是最优的。
Select a query and click Tune to transfer the query to IBM Data Studio to format the query, analyze the access plan, or check whether statistics are current and optimal.
选择一个查询并单击Tune 可将其转化为IBMDataStudio，来格式化查询、分析访问计划、或者检查统计是否存在且最优。
In addition, the high mode does not always guarantee a perfect estimate since no execution plan is guaranteed to be 100% optimal since the plan is based on an estimate.
此外，high模式并非总能保证得到完美的估计，因为既然计划是以估计为基础的，就不能保证执行计划是100%最优的。
Because the DB2 optimizer does not know the values of the parameter markers in the prepare phase, a one-size-fits-all access plan is generated that cannot be optimal in all cases.
由于DB 2优化器在准备阶段不知道参数标记的值，因此生成了一个在所有情况下都不是最优的万能(one - size - fits - all)访问计划。
Because the DB2 optimizer does not know the values of the parameter markers in the prepare phase, a one-size-fits-all access plan is generated that cannot be optimal in all cases.
由于DB 2优化器在准备阶段不知道参数标记的值，因此生成了一个在所有情况下都不是最优的万能(one - size - fits - all)访问计划。
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