MySQL Important Logfiles

MySQL Important Logfiles 

1. Error log file:

During instalation time this file is created , startup & shutdown, hang, maintenance related details are recorded.

show variables like '%log%';

log_error | /var/log/mysqld.log

2. General query log file:

Query related issues, instert, update, delete statements are recorded here.

Bydefault this log is not enabled.

show variables like '%log%';

general_log       | OFF                                   

general_log_file  | /var/lib/mysql/mqmopensource.log  

set global general_log=on/off;

3. Binary log file (STATIC VALUE):

Very useful for auditing like how many records are updated/deleted.

It records changes made to the database.

show variables like '%log%';

log_bin | OFF

log_bin_basename 

set global log_bin=on/off;

show binary logs;

flush logs;

4. Slow query log:

This is also very useful for slow query performance logs

slow_query_log      | OFF                                   |

slow_query_log_file | /var/lib/mysql/mqmopensource-slow.log |

set global slow_query_log=on/off;

show variables like '%time%';

long_query_time | 10.000000 (Seconds)