pt-query digest

I've used pt-query digest ever since I became a MySQL database guy. It is an extremely useful tool, especially when you company refuses to buy profiling tools for you. One drawback is that it is heavy on processing. For example, if you want to process several hours worth of logs it can take over an hour and is heavy on the processing power of the system. I wouldn't ever recommend running it on the same server as a production database because of this.

Today was the first time I actually used it against binary logs. Previously I've only done it on slow query logs. After requesting a copy of the binary logs (still cannot get them for myself), I converted the binary logs to text using mysqlbinlog. 

Here is an example from their documentation:

https://www.percona.com/doc/percona-toolkit/2.2/pt-query-digest.html

mysqlbinlog mysql-bin.000441 > mysql-bin.000441.txt

pt-query-digest --type binlog mysql-bin.000441.txt

Here is how I ran it to get specific time ranges and to save the report to a file:

pt-query-digest --type=binlog --since='2015-10-27 11:22:36' --until='2015-10-27 16:40:49' --limit=100%  mysqllog_all_day.out > mysqllog_tuesday_all_day_digest.txt

There are a lot of options to change how the report is created. Seeing the number of times a query with a specific footprint is executed and a graph of the distribution based on timings is super useful. 

If you want to see more, here are a couple blog posts:

https://www.percona.com/blog/2011/12/29/identifying-the-load-with-the-help-of-pt-query-digest-and-percona-server/

https://www.percona.com/blog/2014/03/14/tools-and-tips-for-analysis-of-mysqls-slow-query-log/