mk-query-digest can help you find the queries that take the longest time to execute as compared to other queries. Optimizing these slow queries will make MySQL run faster by reducing the greatest delays. The real art of query optimization is more nuanced, but the basic goal is the same: find slow queries, optimize them, and increase query response times.
The tool is easy to use; executing mk-query-digest slow-query.log will print the slowest queries in slow-query.log. The tool includes support for "query reviews," for reporting queries you have not yet seen or approved, making frequent log analyses quick and efficient.
Essential MySQL tool No. 2: mydumper
Being able to generate data dumps quickly is vital for backups and server cloning. Unfortunately, mysqldump, which ships with MySQL distributions, is single-threaded and, thus, too slow for data-intensive jobs. Thankfully, the modern replacement, mydumper, uses multiple threads, making it 10 times as faster than mysqldump.
Also known as MySQL Data Dumper, this tool does not manage backup sets, differentials, or other parts of a complete backup plan. It just dumps data from MySQL as quickly as possible, enabling you to complete backups under tight time constraints, such as overnight, while employees are offline, or to perform backups more frequently than you would with mysqldump.
One technical point to know about mydumper is that it locks tables, so it is not the ideal tool for performing backups during operating hours. Then again, professional data recovery costs hundreds of dollars per hour, and you always get a bill even if the data isn't recoverable. mydumper is free and well worth exploring for even basic backups.
mydumper also comes in handy when cloning servers. Other tools perform complete hard drive duplications, but when all you need is MySQL data, mydumper is the fastest way to get it. Servers provisioned in a cloud are particularly suited to cloning using mydumper. Just dump your MySQL data from an existing server and copy it to the new instance.
Cloning is worthwhile for creating slave servers, benchmarking, and profiling, but nowhere is it more vital than in testing and development. Being able to spin up a replica for quick testing before going live is essential for dynamic MySQL environments. With mydumper, you can quickly create a server that is nearly identical to your production server, enabling your test results to better mimic production results.