BPC Auditing

Hi,

Can anyone please explain the following in BPC auditing?

Set Purge frequency..

Save Audit data every..

Why I am asking is, I set the following parameters.

Set Purge frequency.. - 1Day

Save Audit data every..  - 1Hour

But I see that data is not moving to archive tables even after one day(Set Purge frequency.. - 1Day)

and,

data is moving from temp tables to main tables as soon as as I submit ( as per my settings,Save Audit data every..  - 1Hour, I assume that data should stay in temp tables for 1 hour and then move to main reports table for each one hour. isn't it)

I don't understand why it is so difficult to find good document on these from SAP website?

Thanks