Take the 2-minute tour ×
Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. It's 100% free, no registration required.

Just as the title says, where can I see it ?

Are there any config options for it ( like how many ms would determine if a query is slow or not ) ?

share|improve this question
add comment

5 Answers

up vote 10 down vote accepted

You can find it in the default directory, depending on your install. For instance, on my Red Hat, it's /var/log/mysql/

Query time is time, in seconds, over which it should start recording. This can be done at startup and at runtime.

log-slow-queries = /var/log/mysql/mysql-slow.log

long_query_time = 1

share|improve this answer
1  
At my site, I discovered someone has set log_slow_queries=ON. So I have a file in my datadir called ON containing the log. That was confusing... –  Gaius Jan 3 '11 at 22:01
2  
Note that log-slow-queries is deprecated as of 5.1.29. The one to use thereafter is slow-query-log. –  Riedsio Jan 13 '11 at 22:19
1  
Also note that beginning with MySQL 5.1.21, a resolution of microseconds is supported when logging to a file. –  Riedsio Jan 13 '11 at 22:25
add comment

In MySQL : show global variables like '%slow%';

Update : here's a link to the manual: link text

share|improve this answer
    
Can you link to the manual for a short answer like this? –  Brian Ballsun-Stanton Jan 12 '11 at 1:59
add comment

These are the pertinent options (and settings) I generally have/use in all my my.cnfs to log slow queries:

log_output=FILE
slow_query_log=1
slow_query_log_file=/var/log/mysql/mysql.slow 
long_query_time=0.001 
log-queries-not-using-indexes=0

Note that for long_query_time,

Beginning with MySQL 5.1.21 ... a resolution of microseconds is supported when logging to a file.

share|improve this answer
add comment

Search your mysqld config file (usually, /etc/my.cnf)

At your shell:

grep slow /etc/my.cnf
share|improve this answer
add comment

Here is something to consider as well :

If you use the option

log-output=TABLE

in you /etc/my.cnf file, look for the slow log to be a CSV storage engine based table located in, of all places, the mysql schema.

This affects the general log as well, once you enable it.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.