That number is used as an index into the partitioning map to select the database partition for that row.

这个号码将用于作为分区映射的一个索引，以选择那一行所在的数据库分区。

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When a database partition group is created or modified, a partitioning map is associated with it.

当创建或修改一个数据库分区组时，就会有一个与之关联的分区映射。

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The partitioning map is created when a database partition group is created.

当创建数据库分区组时，同时会创建分区映射。

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