MySQL Log Setting

MySQL Log Setting

MySQL has the following logs:

Log Type	Description
Error Log	Problems encountered starting, running, or stopping mysqld
General Query Log	Established client connections and statements received from clients.
Binary Log	All statements that change data(also used for replication).
Slow Query Log	All queries that took more than 'long query time' seconds to execute or didn't use indexes.

 

 

Log control at server startup:

[version >= 5.1.9]

--log-output=FILE --general_log --slow_query_log --general_log_file=/var/log/mysql/general.log --slow_query_log_file=/var/log/mysql/slow.log

 

[version < 5.1.9]

--log=/var/log/mysql/general.log

 

Log control at runtime:

Varibale	Scope	Description
log_output	global	logging destination
general_log	global	enable(ON) or disable(OFF) the general log
slow_query_log	global	enable(ON) or disable(OFF) the slow query log
general_log_file	global	the log file name
slow_query_log_file	global	the log file name
sql_log_off	session	enable(ON) or disable(OFF) the general log

 

Example:

SET GLOBAL general_log = 'OFF';
SET SESSION sql_log_off = 'ON';

 

Log Flush

Log flushing occurs when you issue a FLUSH LOGS statement.