Can't turn on MySQL log for slow queries

Question

I'm trying to log MySQL slow queries, but I can't turn it on, I will explain all my steps:

• I Edit my.cnf and add the following lines

long_query_time = 1
slow_query_log_file = /home/mysql/slow_queries.log
slow_query_log = 1

• Give mysql user permitions to write on the file

chown -R mysql:mysql /home/mysql

• Restart the service

/etc/init.d/mysqld restart

I check the MySQL logs and don't find any error during the restart!

Answer 1

This depend of you MySQL version. If you're running MySQL 5.0, you need to use :

log_slow_queries = 1

http://dev.mysql.com/doc/refman/5.0/en/server-options.html#option_mysqld_log-slow-queries

And only with new version (MySQL 5.1), you can use this :

slow_query_log = 1

http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html#sysvar_log_slow_queries