对于带变量的sql语句，优化器会使用一个默认过滤因子在绑定时确定最佳访问路径。

For SQL statements with variables, the optimizer USES a default filter factor to determine the best access path at bind time.

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但是，现在的普遍情况是，这些风险因子在保单制定时会有所观测，之后的变化影响就不做考虑。

But now thing is these risk factors in the policy making process is observed, while after that their changes will not be considered.

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结果表明：当锥角固定时，冲量和冲量耦合系数随无量纲因子先增大后减小，极大值对应的无量纲因子仅与气体比热比相关；

The results show that, impulse and impulse coupling coefficient firstly increase and then decrease with the augment of the dimensionless factor when cone angle is fixed;

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