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。

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This includes information such as response time, an SQL statement's count of that transaction, cost estimation, sorting statistics, locking related details, and so on.

这些信息包括响应时间、此事务的sql语句计数、估计的成本、排序统计数据、与锁相关的详细信息等等。

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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。

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The mathematical sciences prize was awarded to David L. Donoho for his "contributions to modern mathematical statistics and in particular the development of optimal algorithms for statistical estimation in the presence of noise and of efficient techniques for sparse representation and recovery in large data-sets, " the committee said.

WSJ: Six U.S.-Born Scientists Win Asian Prize