While a normal index can be used, it wastes a lot of space for nulls you are probably not going to query against.
如果使用普通索引的话，即使你并不打算对它进行查询，它也会因为null值浪费大量的空间。
It is calculated through the translation of casualty and direct loss into a normal index, which is a method of simplicity and applicability.
灾级大小是将一次灾害中死亡、伤害和直接经济损失数折算成规范化指数后计算出来的。其方法简单易行，且适用性强。
It is calculated through the translation of casualty and direct loss into a normal index, which is a method of simplicity and applicability.
灾级大小是将一次灾害中死亡、伤害和直接经济损失数折算成规范化指数后计算出来的。其方法简单易行，且适用性强。
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