Ve skutečnosti to můžete udělat docela snadno:
-- Select everything into temp table
Select * Into
#tmpBigTable
From [YourBigTable]
-- Drop the Primary Key Column from the temp table
Alter Table #tmpBigTable Drop Column [PrimaryKeyColumn]
-- Insert that into your other big table
Insert Into [YourOtherBigTable]
Select * From #tmpBigTable
-- Drop the temp table you created
Drop Table #tmpBigTable
Pokud máte Identity Insert On v "YourOtherBigTable" a sloupce jsou naprosto identické, budete v pořádku.