What's the most efficient way to select the last n rows in a table without changing the table's structure?

Question

What\'s the most efficient way to select the last n number of rows in a table using mySQL? The table contains millions of rows, and at any given time I don\'t know how large

Answer 1

Actually the right way to get last n rows in order is to use a subquery:

(SELECT id, title, description FROM my_table ORDER BY id DESC LIMIT 5) 
ORDER BY tbl.id ASC

As this way is the only I know that will return them in right order. The accepted answer is actually a solution for "Select first 5 rows from a set ordered by descending ID", but that is most probably what you need.