Description:
The slow_query_log and slow_query_log_file are listet as dynamic variable in
http://dev.mysql.com/doc/refman/5.1/en/dynamic-system-variables.html
and thus it should be possible to enable them at runtime without having to restart
the server. That does not work.
How to repeat:
mysql> SET GLOBAL slow_query_log := ON;
ERROR 1146 (42S02): Table 'mysql.slow_log' doesn't exist
mysql> SET GLOBAL log_slow_queries := ON;
ERROR 1146 (42S02): Table 'mysql.slow_log' doesn't exist
mysql> SHOW VARIABLES LIKE "%log%";
+-----------------------------------------+--------------------------------+
| Variable_name | Value |
+-----------------------------------------+--------------------------------+
| back_log | 50 |
| binlog_cache_size | 32768 |
| binlog_direct_non_transactional_updates | OFF |
| binlog_format | STATEMENT |
| expire_logs_days | 10 |
| general_log | OFF |
| general_log_file | /var/run/mysqld/mysqld.log |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_locks_unsafe_for_binlog | OFF |
| innodb_log_buffer_size | 1048576 |
| innodb_log_file_size | 104857600 |
| innodb_log_files_in_group | 2 |
| innodb_log_group_home_dir | ./ |
| innodb_mirrored_log_groups | 1 |
| log | OFF |
| log_bin | ON |
| log_bin_trust_function_creators | OFF |
| log_bin_trust_routine_creators | OFF |
| log_error | /srv/mysql/cc-maildb2-test.err |
| log_output | FILE |
| log_queries_not_using_indexes | OFF |
| log_slave_updates | OFF |
| log_slow_queries | OFF |
| log_warnings | 1 |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_size | 1073741824 |
| max_relay_log_size | 0 |
| relay_log | /srv/mysql/mysqld-relay-bin |
| relay_log_index | |
| relay_log_info_file | relay-log.info |
| relay_log_purge | ON |
| relay_log_space_limit | 0 |
| slow_query_log | OFF |
| slow_query_log_file | /var/log/mysql/mysql-slow.log |
| sql_log_bin | ON |
| sql_log_off | OFF |
| sql_log_update | ON |
| sync_binlog | 0 |
+-----------------------------------------+--------------------------------+
38 rows in set (0.00 sec)
mysql> select version();
+------------+
| version() |
+------------+
| 5.1.48-log |
+------------+
1 row in set (0.28 sec)