Deleting the last row on a page

If you delete the last row on a page, the page is deallocated. If other pages on the extent are still in use by the table, the page can be used again by the table when a page is needed.

If all other pages on the extent are empty, the entire extent is deallocated. It can be allocated to other objects in the database. The first data page for a table or an index is never deallocated.