Monthly Archives - April 2015

Optimizer hints in MySQL 5.7.7 – The missed manual

In version MySQL 5.7.7 Oracle presented a new promising feature: optimizer hints. However it did not publish any documentation about the hints. The only note which I found in the user manual about the hints is:

It is now possible to provide hints to the optimizer by including /*+ … */ comments following the SELECT, […]

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Generated (Virtual) Columns in MySQL 5.7 (labs)

About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns.
The idea is very simple: if we store a column

MySQL

`FlightDate` date

1

`FlightDate` date

in our table we may want to filter or group […]

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Test your knowledge: Percona XtraDB Cluster (PXC) quiz

I often talk with people who are very interested in the features of Percona XtraDB Cluster (PXC) such as synchronous and parallel replication, multi-node writing and high availability. However some get confused when operating a real PXC cluster because they do not fully realize the implications of these features. So here is a fun […]

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Indexing 101: Optimizing MySQL queries on a single table

I have recently seen several cases when performance for MySQL queries on a single table was terrible. The reason was simple: the wrong indexes were added and so the execution plan was poor. Here are guidelines to help you optimize various kinds of single-table queries.
Disclaimer: I will be presenting general guidelines and I do […]

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Percona Live & OpenStack Live 2015 wrap-up

Peter Zaitsev kicks off Percona Live 2015
With highlights that included news of Percona’s acquisition of Tokutek, a lively keynote discussion with Apple legend Steve “Woz” Wozniak, scores of technical sessions, tutorials and a festive MySQL community dinner and game night, last week’s Percona Live MySQL Conference and Expo had something for everyone.
More than 1,200 […]

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Considering Sharding with MySQL? Join my April 22 webinar. Questions welcome!

MySQL sharding is one of the most used and surely the most abused MySQL scaling technology. My April 2 Dzone article, “To Shard, or Not to Shard,” proved there is indeed quite an interest in this topic.
As such, I’m hosting a live webinar tomorrow (April 22) that will shed light on questions about sharding with […]

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Profiling MySQL queries from Performance Schema

When optimizing queries and investigating performance issues, MySQL comes with built in support for profiling queries aka
SET profiling = 1; . This is already awesome and simple to use, but why the PERFORMANCE_SCHEMA alternative?
Because profiling will be removed soon (already deprecated on MySQL 5.6 ad 5.7); the built-in profiling capability can only be enabled […]

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Checking table definition consistency with mysqldiff

Data inconsistencies in replication environments are a pretty common. There are lots of posts that explain how to fix those using pt-table-checksum and pt-table-sync. Usually we only care about the data but from time to time we receive this question in support:
How can I check the table definition consistency between servers?
Replication also allow us […]

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Why Percona Acquired Tokutek: by Peter Zaitsev

It is my pleasure to announce that Percona has acquired Tokutek and will take over development and support for TokuDB® and TokuMX™ as well as the revolutionary Fractal Tree® indexing technology that enables those products to deliver improved performance, reliability and compression for modern Big Data applications.
At Percona we have been working with the […]

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