步骤 2.5：验证选择性估计

Step 2.5: Verify the selectivity estimates

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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。

Given accurate statistics, the query optimizer generally comes up with correct selectivity estimates.

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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。

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.

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