How do you query the "Modified" and "Modified By" headings?

Question

We're in the process of migrating a bunch of sites and upgrading to SP2013 from SP2010. We are trying to find a way to see when various sites have been updated. If they haven't been updated in quite some time, and the business doesn't have a need for the site/resource, then we're not going to migrate and upgrade it.

Is there a way to run a report from Central Admin or author a query in TSQL to ascertain this information?

If you have other ideas on how to perform something similar, I'm open to read what you've done, thanks!

Answer 1

I have done something similar recently. The most reliable way to do this is to use a SPSiteDataQuery and search thereby whole Site for all Items. Using a PowerShell Script you can execute this query and retrieve the latest changed Items, Documents, Webs etc. per Site oder per SiteCollection.