How can I enable MySQL's slow query log without restarting MySQL?

Question

I followed the instructions here: http://crazytoon.com/2007/07/23/mysql-changing-runtime-variables-with-out-restarting-mysql-server/ but that seems to only set the threshold

Answer 1

For slow queries on version < 5.1, the following configuration worked for me:

log_slow_queries=/var/log/mysql/slow-query.log
long_query_time=20
log_queries_not_using_indexes=YES

Also note to place it under [mysqld] part of the config file and restart mysqld.