Emergency

Monthly Archives: February 2013

CentOS 5.8 users: your UTF-8 data is in peril with Perl MySQL

CentOS 5.8 and earlier use Perl module DBD::mysql v3.0007 which has a bug that causes Perl not to flag UTF-8 data as being UTF-8.  Presuming that the MySQL table/column is using UTF-8, and the Perl …

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MySQL 5.5 and MySQL 5.6 default variable values differences

As the part of analyzing surprising MySQL 5.5 vs MySQL 5.6 performance results I’ve been looking at changes to default variable values. To do that I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 …

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Solving RPM installation conflicts in CentOS 5 and CentOS 6

Lately we’ve had many reports of the RPM packages for CentOS 5 (mostly) and CentOS 6 having issues when installing different combinations of our products, particularly with Percona Toolkit for MySQL. Examples of bugs related …

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NoSQL is Great, But You Still Need Indexes

I’ve said it before, and, as is the nature of these things, I’ll almost certainly say it again: your database performance is only as good as your indexes. That’s the grand thesis, so what does …

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Mystery Performance Variance with MySQL Restarts

Based on a lot of surprising comments about my MySQL 5.5 vs 5.6 performance post I decided to perform deeper investigation to see where my results could go possibly wrong. I had set up everything …

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Analyzing Slow Query Table in MySQL 5.6

Next week I’m teaching an online Percona Training class, called Analyzing SQL Queries with Percona Toolkit.  This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database response time …

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Percona MySQL University comes to Toronto on March 22

Following our events in Raleigh, Montevideo, Buenos Aires, Percona MySQL University comes to Toronto on March 22nd. This is going to our most dense event yet, absolutely packed with information. Even though we have just …

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Percona MySQL Webinar: Really Large Queries: Advanced Optimization Techniques, Feb. 27

Do you have a query you never dared to touch? Do you know it’s bad, but it’s needed? Does it fit your screen? Does it really have to be that expensive? Do you want to …

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Is MySQL 5.6 slower than MySQL 5.5?

There have been a number reports/benchmarks showing MySQL 5.6 to be slower than MySQL 5.5 on variety of workloads. There are many possible reasons and I believe we will learn about many of them in …

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Using MySQL Sandbox with Percona Server

One of the most useful tools if you’re working with multiple versions of MySQL Servers is MySQL Sandbox which allows you to maintain many different versions of MySQL, Percona Server, MariaDB. If you’re just working …

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