Yearly Archives - 2015

Django with time zone support and MySQL

This is yet another story of Django web-framework with time zone support and pain dealing with python datetimes and MySQL on the backend. In other words, offset-naive vs offset-aware datetimes.
Shortly, more about the problem. After reading the official documentation about the time zones, it makes clear that in order to reflect python datetime […]

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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 (good and bad)

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 the […]

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