How to see data receiving in Piwik at database table?

Hi,
I have several domains registered in Piwik. As not all this domains are managed by me, I need to know where I safetely can see on Piwik DB data are received for a domain.

Usages would be, to just scheduled delete the domain after time X, if no data will be received.

Or maybe there is already a plugin available, what provide such a function??

Maik