I use find_by_sql to execute a query which takes around 120 seconds to execute in Ruby. When I execute the same request using SQLyog (GUI), the requests takes around 15 seconds to execute.
Here's roughly what the query looks like:
SELECT DAY(date_time) "day", COUNT( * ) "count" FROM table WHERE (id = some_id) AND(YEAR(date_time) = 2006) AND(MONTH(date_time) = 8) AND(some_string IN ('some short string') ) GROUP BY DAY( date_time );
I'm querying about a million records.