MySQL Forums :: Triggers :: limit number of rows using a trigger

another issue is that my log grows once a second for 30 days so I end up with around 2.7 million rows so "COUNT(*)" may end up slow.

perhaps I could just use the time stamp like this?:

SELECT MIN (last_update) INTO @min FROM a_test;
IF NEW.last_update - @min >= 30 THEN
DELETE FROM a_test ORDER BY last_update LIMIT 1;