[xwiki-users] class property deletion / sql query

Hi guys, I'm aware of the fact, that there is not yet a feature for deleting class properties. I think I read somewhere about a workaround for this but can't find it anymore. I don't care, if the data remains for some documents, but I do not want to get it displayed, nor do I want the property to be fillable in new pages. Can you give me a hint what to do so, raw SQL is cool as well, if that is the only way. A second question, since I'm not yet an expert on xwiki datastructure and database model (I know of the xwiki.org docs on this) is the following: I want the pagealreadyexists page to show me, what template was used for the creation of the existing document. Like: "Document 'blabla' exists and was built using template (class/object) of type 'blablabla'." I think this should be easy, how do I get the object name of the used template? Thanx guys, Sebastian