Unique Index

基本解释

The primary key and any unique index of the table must be a superset of the associated partitioning key.
表的主鍵和所有惟一索引都必須是相關分區鍵的超集。
On a federated system, unique index information might be required to perform an UPDATE/DELETE operation for some data sources.
在一個聯邦系統上，爲了爲某些數據源執行 UPDATE/DELETE 操作，需要惟一的索引信息。
In other words, all columns that are part of the partitioning key must be present in the primary key or unique index definition.
換句話說，作爲分區鍵一部分的所有列都必須出現在主鍵或惟一索引定義中。

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