The other day I had a customer ask if it was possible to determine what the break down was in the NamedProps table for a mailbox store.
As you may recall from my posting on the Exchange Team blog (http://blogs.technet.com/b/exchange/archive/2010/07/29/3410545.aspx), the maximum number of named properties that can ever be created is 32,767 per database. NamedProps consist of Authenticated Users & Non-Authenticated Users. It doesn't matter if the user is authenticated or not - they all go into the same NamedProps table. So you could have 32k created all by authenticated users, or 32k all created by unauthenticated users, or 10k created by unauthenticated and 22k by authenticated, or whatever... it doesn't matter who created them, the bottom line is that the maximum is 32k rows in that table.
So the question was:
Is there a way to determine how many of the NamedProps are Authenticated Users and how many are Non-Authenticated Users?
The unfortunate answer is no. There is no way to determine how many of the NamedProps are Authenticated Users and how many are Non-Authenticated Users.
The only way that it could possibly be done is if it was captured at the time it is written to the table and there is not tool available to do this. Will there be one in the future? I haven’t heard of any plans for one, but you never know.