| 释义 |
se·lec·tiv·i·ty 英sɪˌlekˈtɪvɪtiː, ˌsiːlek-美sɪˌlɛkˈtɪvɪti, ˌsilɛk-AHDsĭ-lĕk'tĭvʹĭ-tē, sē'lĕk- 高COCA³³⁶³⁸BNC²²²¹⁶iWeb²³⁹⁰³Economist³⁴³¹⁸⁺³
基本英英搭配记法近义反义派生词例句Thesaurus例句
n.选择性⁹⁷;选择度³名词复数selectivities
Noun:
the property of being selectiveselective选择的relative selectivity相对选择性effective selectivity有效选择性interionic selectivity离子间选择selectivity index选择性指数variable selectivity可变选择性selectivity characteristic选择性特性selectivity curve选择性曲线selectivity control选择性调整selectivity coefficient选择系数spectrum selectivity频谱选择性overall selectivity总选择性catalyst selectivity催化剂选择性…frequency selectivity频率选择性skirt selectivity边缘选择性selectivity factor选择性因数channel selectivity信道选择性polarization selectivity偏振选择性solvent selectivity溶剂选择性spectral selectivity光谱选择性
se-分|离开lect-选择iv形容词=-ive-ity名词⇒n.选择性⁹⁷;选择度³n.无线电选择性⁹⁷;精选;选择;物选择能力;选择率;供选择的状态;分离性蒋争熟词记忆select挑选-ivity名词后缀⇒选择；挑选；选择性词根记忆select选择近义词 option选择权discernment眼光discrimination歧视
Pelectroselectivity电选择性Ppseudo-selectivity准选择性Pstereoselectivity立体选择性Pregioselectivity区域专一性区域选择性
名词100%
用作名词The conclusion proved that,both of them have good flotationselectivity.结果表明，它们对氟碳铈矿均具有良好的浮选选择性。noun.discrimination
同义词 acumen,acuteness,astuteness,bias,clearness,decision,difference,differentiation,discernment,distinction,judgment,keenness,penetration,perception,perspicacity,preference,refinement,sagacity,sense,separation,shrewdness,subtlety,taste,understandingastucity,percipience,selectiveness
反义词 dislike,hate,hatred,ignorance,indecision,stupidity
selectivenessnoun discrimination
acumen,acuteness,astucity,astuteness,bias,clearness,decision,difference,differentiation,discernment,distinction,judgment,keenness,penetration,perception,percipience,perspicacity,preference,refinement,sagacity,sense,separation,shrewdness,subtlety,taste,understanding
specificitynoun state of being precise or particular
distinction,exactitude,idiosyncrasy,meticulousness,particularity,precision,relevance,selectivity And all ion channels are selective for a single type of ion, and we can think about how that selectivity takes place, and that's where this idea of atomic radius is going to become very important.
所有的离子通道都是仅对某一种离子具有选择性的，而我们可以来想一想这种选择性是如何发生的，这也就是原子半径这个概念将会变得，非常重要的地方。163
At the same time, we also have found differences in signal selectivity that may allow us to target some bacteria while ignoring others.
同时，我们还发现了信号选择性的差异，这能够使我们针对一些特定的细菌而不影响到其他。 yeeyan
In turn, the estimated number of rows is based on the selectivity of each conditional expression that is used within the WHERE clause.
被评估的行数则基于 WHERE 子句里所使用的每个条件表达式的选择性。 ibm
In other words, the optimizer overestimated the selectivity of the local predicates on the table.
换句话说，优化器过高估计了本地谓词对表格的选择性。 ibm
The optimizer uses data distribution information generated by UPDATE STATISTICS to calculate selectivity for the filters in the query.
优化器使用 UPDATE STATISTICS所生成的数据分布信息来计算查询中筛选器的选择性。 ibm
What all of these channels have is what's called a selectivity filter, so this filter filters out the type of ion that's going to be allowed through.
这些离子通道都有的一部分,就是所谓的选择性过滤器，这个过滤器,会滤过允许穿过的离子。163
But the selectivity calculated in this way is not as accurate as selectivity calculated using data distribution.
但是，使用该方式计算的选择性不如使用数据分布计算的选择性准确。 ibm
Each join reduces the size of the fact table by one- tenth due to selectivity of the table filter on each dimension table.
由于每个维度表过滤的选择度，每次连接都会减少事实表大小的十分之一。 ibm
For example, if the indexed column has literal values and NULL values, then the selectivity is equal to the number of distinct keys in the index.
例如，如果索引列包含字面值和 NULL值，那么其选择性就等于索引中不同的键的数目。 ibm
For simple cost calculations, we suppose an idealized number of rows in each table and assume that the selectivity of the filter on each dimension table is1/10 for the following query.
对于简单的成本计算，我们假设每个表中都有足够的行数，对于以下查询，每个维度表的过滤选择度为1/10。 ibm
For the exceptional situations where the optimizer cannot choose an optimal query execution plan, DB2 has added features such as the SELECTIVITY clause and optimization guidelines.
对于优化器不能选择最佳查询执行计划的例外情况， DB2已经增加了诸如 SELECTIVITY子句和优化指南之类的特性。 ibm
Given accurate statistics, the query optimizer generally comes up with correct selectivity estimates.
如果有了准确的统计信息，那么查询优化器一般能够得出正确的选择性估计。 ibm
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。 ibm
In particular, it is rather hard for the optimizer to determine the costs and the selectivity of such an index scan.
而且，优化器很难判断那样的索引扫描的成本和选择性。 ibm
In reality, the narrative is far more complex, and the implications far less sunny for students as well as colleges caught up in the cruel cycle of selectivity.
在现实中，叙事更为复杂，影响远不如对学生以及陷入了残酷的周期可达选择性高校阳光普照。 yeeyan
In terms of sensitivity and selectivity, the current technology out there is still inferior.
但说到灵敏度和选择度，目前现有的科技设备还处于劣势。 hjenglish
Indexes on the foreign keys referencing tables with few rows have low selectivity, and the utility of requiring the index has always been questionable.
外键上的索引所引用的表行数较少，选择性较少，需要索引的实用程序一直遭受质疑。 ibm
Missing statistics can cause the optimizer to overestimate or to underestimate the selectivity of a predicate, and eventually to select an inefficient access path.
丢失的统计数据会让优化器高估或低估谓词的选择性，最终会选择低效的访问路径。 ibm
Mustapha's modification lets food scientists use the PCR test to capitalize on its speed, selectivity and sensitivity, but avoid false-positive tests by differentiating between dead and live cells.
幕斯塔法的修改使食品科学家在使用 PCR测试时，可以有效利用其高效性、有选择性和敏感性，并且通过区分死亡细胞和活细胞避免误测。 yeeyan
Our ears have only evolved to respond to sound with very high sensitivity and high selectivity.
人类的耳朵对声音的反应,极为敏感，也极有选择性。163
Refer to Chapter10 of the Performance Guide for the detailed table that the optimizer uses to calculate selectivity in the absence of data distribution.
关于在缺乏数据分布的情况下，优化器用以计算选择性的详细表，请参阅 Performance Guide的第10章。 ibm
So it is obvious that the accuracy of selectivity estimation depends upon how often you run UPDATE STATISTICS.
因此，选择性估算的准确性显然基于您运行 UPDATE STATISTICS的频率。 ibm
Sometimes, due to a skew in the distribution of data, the nature of the predicate or the query, or insufficient statistics, the optimizer's selectivity estimates may not be accurate.
有时候，由于在数据分布上的一点偏差，加上谓词或查询的特性，或者由于统计信息不充分，可能导致优化器的选择性估计不准确。 ibm
The overall benefit of pushing down keys to filter fact table rows is directly proportional to the filter selectivity of the dimension table.
通过下推键来过滤事实表行的整体效果直接与维度表的过滤选择度成比例。 ibm
This can occur if the IN list contains parameter markers or host variables which prevent the optimizer from using catalog statistics to determine the selectivity.
如果 IN列表中包含参数标记符或主机变量，使优化器不能使用编目统计信息来确定选择性，就会出现这种情况。 ibm
This information can then be included as part of the optimizer decision during costing for selectivity and cardinality estimates for qualified queries which do not need to reference the view directly.
然后，这些信息被包括进来，用于帮助优化器在为那些符合条件的查询这些查询不需要直接引用视图的选择性估计和基数估计计算成本时做决定。 ibm
This suggests a much better predicate selectivity than it appears to be!
这表明谓词选择性比其表现出来的还要好！ ibm
Selectivity is key to its success.
选择性是成功关键。 ecocn |