... spectrum selectivity 频谱选择性 overall selectivity 总选择性 catalyst selectivity 催化剂选择性...
基于1个网页-相关网页
There is much less index access and no index AND'ing so that the overall performance can be one or two order of magnitude better - depending on predicate selectivity.
只有相当少的索引访问且没有索引 AND'ing,这样整体性能将提高一个或两个数量级 —— 取决于谓词选择。
These expressions prevent the optimizer from assigning valid cardinality or selectivity estimates and can in turn affect the overall plan and the join method.
上面表达式使优化器不能有效分配基数或选择性消耗,可能会反过来影响整个执行计划。
应用推荐