This many not be something you can use in your application. This will be helpful during demonstrations of SQL Serve internals.
This sample code will tells you which row is in which page. Highlighted section has undocumented function.
1: USE tempdb2: GO3:8: )9:11:13: GO 1000014:16: CROSS APPLY fn_PhysLocCracker (%%PHYSLOC%%) pl17:
Result of this is,
SlotId is the record id of the page.