Here is the SQL statement:
|SELECT * FROM sf_CmsControlProperty |
|INNER JOIN sf_CmsCtrlLinks |
| ON sf_CmsControlProperty.ControlID = sf_CmsCtrlLinks.ControlID |
is the table that makes many-to-many relation to live pages. Relations to history are kept in table sf_StagedCtrlLinks
Sitefinity currently does not make use of many-to-many relation between pages and controls but this is planed for future features. When dropping a control on a page you will be able to specify it as reference to a control form other page instead of creating new instance.
I hope this helps. Don’t hesitate to ask if you need further information.
the Telerik team