What is PCT for a materialized view?

Saw it in a reference manual. What is PC开发者_如何转开发T for a materialized view?

What is "Partition Change Tracking"?

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From the Oracle documentation itself :

"It is possible and advantageous to track freshness to a finer grain than the entire materialized view. The ability to identify which rows in a materialized view are affected by a certain detail table partition, is known as Partition Change Tracking. When one or more of the detail tables are partitioned, it may be possible to identify the specific rows in the materialized view that correspond to a modified detail partition(s); those rows become stale when a partition is modified while all other rows remain fresh."