From a Microsoft Course (presented by a third party) I learned that when a table has a clustered index even non-clustered indexes hit the clustered index.
When there is not a clustered index (Heap) as I understand it Nonclustered indexes reference directly into the pages of the table.
Assuming correct understanding, why do the non-clustered indexes reference the clustered index instead of the underlying data pages of the table directly? It seems like this would be less overhead referencing the table data pages directly.