How to enable MySQL general log?

Question

I would like to enable the MySQL General Log to view all the (slow) queries. I'm using XAMPP as server and have no idea how to enable it. I can't find a good guide on the internet.

Can someone help me please?

Thanks!

Answer 1

The flags you need to activate the general log and the slow on in the MySQL Documentation

• log (to activate the general log)
• general log (to name the log file)
• slow query log (to activate the slow log)
• log output (specify either FILE or TABLE for where logging info is written)

I would recommend using log-output=TABLE

It will save the logging of general log and slow log info to MySQL tables

• mysql.general_log
• mysql.slow_log

You should convert them to MyISAM. That way, you can index the tables by the timestamp and perform SELECT queries from them.

By default, these files use the CSV storage engine.

mysql> show create table mysql.general_log\G
*************************** 1. row ***************************
 Table: general_log
Create Table: CREATE TABLE `general_log` (
 `event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 `user_host` mediumtext NOT NULL,
 `thread_id` int(11) NOT NULL,
 `server_id` int(10) unsigned NOT NULL,
 `command_type` varchar(64) NOT NULL,
 `argument` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log'
1 row in set (0.09 sec)
mysql> show create table mysql.slow_log\G
*************************** 1. row ***************************
 Table: slow_log
Create Table: CREATE TABLE `slow_log` (
 `start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 `user_host` mediumtext NOT NULL,
 `query_time` time NOT NULL,
 `lock_time` time NOT NULL,
 `rows_sent` int(11) NOT NULL,
 `rows_examined` int(11) NOT NULL,
 `db` varchar(512) NOT NULL,
 `last_insert_id` int(11) NOT NULL,
 `insert_id` int(11) NOT NULL,
 `server_id` int(10) unsigned NOT NULL,
 `sql_text` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log'
1 row in set (0.05 sec)
mysql>

Convert the general log and index it by event_time:

SET @old_log_state = @@global.general_log;
SET GLOBAL general_log = 'OFF';
ALTER TABLE mysql.general_log ENGINE = MyISAM;
ALTER TABLE mysql.general_log ADD INDEX (event_time);
SET GLOBAL general_log = @old_log_state;

Convert the slow log and index it by start_time:

SET @old_log_state = @@global.slow_query_log;
SET GLOBAL slow_query_log = 'OFF';
ALTER TABLE mysql.slow_log ENGINE = MyISAM;
ALTER TABLE mysql.slow_log ADD INDEX (start_time);
SET GLOBAL slow_query_log = @old_log_state;

Give it a Try !!!

• Luuk: The link "log (to activate the general log)" should be changed (for MySQL 8.0) to general_log