How do I delete either the first or last set of rows in a dynamic fashion

Question

I would like to delete the first 100 rows or the last 100 rows in a certain table (ordered by the primary key).

Note: Lots of data is being spooled into this table.<

Answer 1

for first 100,

DELETE FROM table ORDER BY  ASC limit 100

and for last 100,

DELETE FROM table ORDER BY  DESC limit 100