partitioned IOT的 partition key为啥一定要是primary key的子集呢

lory

For index-organized tables, the set of partitioning columns must be a subset of the
primary key columns. Because rows of an index-organized table are stored in the
primary key index for the table, the partitioning criterion has an effect on the
availability. By choosing the partition key to be a subset of the primary key, an insert
operation only needs to verify uniqueness of the primary key in a single partition,
thereby maintaining partition independence.

10g administration里的一段描述，为啥一定partition key为啥一定要是primary key的子集呢

看得不是很明白，能具体举个例子说明么

lory

http://richardfoote.wordpress.com/2007/12/20/local-index-issue-with-partitioned-pk-and-unique-key-constraints/
今天在网上查了好久，参考上面这个连接，里面说了为啥unique index 做local partition时，partition column 必须是index column的子集。情况是一样的

psufnxk2000

因为 它 主键索引 也是分区的。