Finally, Rollup is capable of intelligently utilizing the best interval available. If you’ve worked with summarizing features of other products, you’ll find that they can be limiting. If you configure rollups at daily intervals… your queries and charts can only work with daily intervals. If you need a monthly interval, you have to create another rollup that explicitly stores monthly averages, etc.
The Rollup feature stores data in such a way that queries can identify the smallest available interval and use that for their processing. If you store rollups at a daily interval, queries can be executed on daily or longer intervals (weekly, monthly, etc) without the need to explicitly configure a new rollup job. This helps alleviate one of the major disadvantages of a rollup system; reduced flexibility relative to raw data.