This is actually the per-partition cardinality estimate, and not the total cardinality. 这实际上是每个分区的基数估计值,不是完整的基数。
With this method, we can collect real cardinality for access plan operators. 通过这种方法,我们就能够为访问操作者收集实际基数。
For example, while OWL Lite supports cardinality constraints, it only permits cardinality values of0 or1. 例如,虽然OWLLite支持基数约束,但是只支持基数值0或1。
You may have noticed that the query access plan itself did not change with the increase in cardinality estimate. 您可能已经注意到了,查询访问计划本身并未随着基数估计值的增大而改变。
Therefore, omitting the maximum cardinality does not have any impact on the amount of allocated memory. 因此,省略最大基数不会对已分配的内存量产生任何影响。
The optimizer is dependent on accurate cardinality estimates to properly compute the cost of each query access plan considered. 优化器凭借精确的基数估计值来准确计算出每一个待定查询访问计划的成本。
This is close, but higher than the real cardinality. 接近但高于实际的行数。
There are eight qualifying records after applying the local predicate ( Outer Input Cardinality value is8). 在应用本地谓词以后,有8条合格的记录(外部输入基数值是8)。
Cardinality estimation is a process by which the optimizer uses statistics to determine the size of partial query results after predicates are applied or aggregation is performed. 基数估计是这样一种过程:在应用了谓词或执行了聚集之后,优化器使用统计信息确定部分查询结果的大小。
And the cardinality is corrected at the RIDSCN and FETCH operators, which accounts for the statistical correlation between the IN and equality predicates. 而且RIDSCN和FETCH操作符的基数也被更正了,这样就可以说明IN谓词和等式谓词间的统计关联。
With three predicates applied in the WHERE clause, assuming they are independent results in the optimizer underestimating the cardinality. 在WHERE子句中应用了三个谓词,如果假设它们是独立的话,会导致优化器低估基数。
Note: The Relational DAS assumes that all containment relationships are cardinality one-to-many. 注意:关系型DAS假定所有包容关系都是一对多的二元关系。
The field definitions contain the field name and type, as well as the cardinality ( which is the number of values this field can have). 该字段定义包含字段名和类型,以及基数(这是该字段可拥有的值的数量)。
The examples described in this article are simple in order to illustrate how to improve the cardinality estimate. 为了更好的说明如何提高基数估计值,本文中所描述的例子都很简单。
The number shown in each node is the optimizer's estimate for the cardinality of the underlying data source or operation node. 每一个节点上显示的数字都是优化器对基础数据源或操作节点的基数的估计。
The same cardinality estimate is carried up, and no counts are needed for these two operators. 同样进行基数估计,但是这两个操作不需要计数。
The application of one or more predicates may reduce the output stream cardinality. 应用一个或更多谓词可以减少输出流基数。
Specify attribute types and cardinality: Specify several properties of one attribute, and then repeat that step for all attributes. 指定属性类型和基数:指定一个属性的几个特征,然后为所有属性重复该步骤。
At each operator in the access plan, the optimizer estimates the cardinality output from the operator. 对于访问计划的每个操作符,优化器将估计该操作符的基数输出。
The value of the second argument to TRIM_ARRAY must be a value between 1 and the cardinality of the first argument. 针对TRIMARRAY的第二个参数的值必须是1和第一个参数的基数之间的值。
This example illustrates the effect that partial statistics have on the ability of the optimizer to estimate the cardinality. 这个示例解释说明了部分统计信息对于优化器估计基数的能力的影响。
Join cardinality is the number of rows produced when two row sets are joined together. 连接行集数是两个行集被连接在一起时产生的行集数。
That is, the restrictions constrain the cardinality of that property on instances of that class. 这类约束应用于那个类的实例时就会给出属性的基数信息。
The base cardinality can be captured by analyzing the table. 基本的行集数能通过分析表被捕获。
A generalized morphological transform based on the set cardinality was presented. 提出了一种基于集合势的广义形态变换形式。
The algorithm of merging is based on maximum cardinality matching and can merge some LUTs. 该算法基于图的最大基数匹配,将部分查找表进行合并,减小了映射结果的面积开销。
So how optimizer work out the cardinality with range filter in TABLE JOIN? 那么优化器怎么出来表连接中的范围扫描呢?
This problem is a generalization of the problem of finding the maximum cardinality clique of an unweighted graph. 这个问题是寻找无权图的最大团问题的推广。
There may also be multiple variations for gender and cardinality. 性别和基数也可能有多种变体。