Getting mutex information from MySQL’s performance_schema

We have been using SHOW ENGINE INNODB MUTEX command for years. It shows us mutex and rw-lock information that could be useful during service troubleshooting in case of performance problems. As Morgan Tocker announced in his blog post the command will be removed from MySQL 5.7 and we have to use performance_schema to get […]

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Using YUM to install specific MySQL/Percona Server versions

Sometimes it is desired to use particular software versions in production, and not necessary the latest ones. There may be several reasons for that, where I think the most common is when a new version should spend some time in testing or a staging environment before getting to production. In theory each new version […]

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The MySQL Query Cache: How it works, plus workload impacts

MySQL query cache

The MySQL query cache is one of the prominent features in MySQL and a vital part of query optimization. It is important to know how the MySQL query cache works, as it has the potential to cause significant performance improvements – or a slowdown – of your workload.
The MySQL query cache is a global one shared among […]

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How small changes impact complex systems – MySQL example

If you’ve been studying complex systems you know what minor changes might cause consequences of much greater proportions, sometimes causing some effects that are not easily explained at first. I recently ran across a great illustration of such behavior while doing MySQL benchmarks which I thought would be interesting to share.
I’m using a very […]

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