DBMS client applications need to store SQL query results in local memory or local files. The format is flat and the fields are ordered -- that's "serialization". The most important serializer format uses human-readable markup, like
[start of field] [value] [end of field]
and the important ones in the MySQL/MariaDB world are CSV (what you get with SELECT ... INTO OUTFILE or LOAD INFILE), XML (what you get with --xml or LOAD XML), and JSON (for which there are various solutions if you don't use MySQL 5.7).

The less important serializer format uses length, like
[length of value] [value]
and this, although it has the silly name "binary …

This blog discusses how to find and address badly written queries using ProxySQL.

All of us are very good in writing good queries. We know this to always be true!

But sometimes a bad query escapes our control and hits our database. There is the new guy, the probie, who just joined the company and is writing all his code using SELECT * instead of WHERE. We’ve told him “STOP” millions of times, but he refuses to listen. Or a there is a new code injection, and it will take developers some time to fix and isolate the part of the code that is sending killing queries to our database.

The above are true stories; things that happen every day in at least few environments.

Isolating the bad query isn’t the main problem: that is something that we can do very fast. The issue is identifying the code that is generating the query, and disabling that code without killing the whole application.

That …

I just created the Budapest MySQL Meetup group. I hope there will be interest for that, the first event is under organising. Check it if you are near Budapest!

Percona announces the GA release of Percona Server 5.7.14-7 on August 23, 2016. Download the latest version from the Percona web site or the Percona Software Repositories.

Based on MySQL 5.7.14, including all the bug fixes in it, Percona Server 5.7.14-7 is the current GA release in the Percona Server 5.7 series. Percona’s provides completely open-source and free software. Find release details in the …

Introduction

This is part two of a five part blog series to explore InnoDB internals by looking at the related tunable system variables. In part one we covered variables that had the greatest impact on memory, and in this instalment we will cover the variables that have the greatest impact on the file structure of InnoDB as well as how data is written to logs, which can have a large impact on transaction commit overhead. Originally I was considering putting all the I/O related InnoDB related variable in one post, however that’s a lot of ground to cover. Instead you can look forward to an upcoming instalment of this blog series that will cover I/O as it relates to table data.

Before we begin, I would like to emphasize something that was written in part one of this blog post series.

“I should note that while tuning recommendations are provided, this objective of this blog post series was NOT meant to be a tuning …

ConFoo Montreal: March 8th-10th 2016

Want to get your web development ideas in front of a live audience? The call for papers for the ConFoo Montreal 2017 web developer conference is open! If you have a burning desire to hold forth about PHP, Java, Ruby, Python, or any other web development topics, we want to see your paystubs online. The window is open only from August 21 to September 20, 2016, so hurry. An added benefit: If your proposal is selected and you live outside of the Montreal area, we will cover your travel and hotel.

You’ll have 45 minutes to wow the crowd, with 35 minutes for your topic and 10 minutes for …

I just created the Budapest MySQL Meetup group. I hope there will be interest for that, the first event is under organising.  Check it if you are near Budapest!   Share This:

Remember to join us Tuesday, August 30th for the first part of our upcoming webinar trilogy on MySQL Query Tuning. This first of three in-depth webinar sessions led by Krzysztof Książek, Senior Support Engineer at Severalnines, covers MySQL query tuning process and tools.

When done right, Tuning MySQL queries and indexes can increase the performance of your application and decrease response times. We will be covering this complex topic over the course of three webinars of 60 minutes each, so feel free to also register for parts 2 & 3 here.

In this first part of the trilogy we will discuss building, collecting, analysing, tuning and testing processes as well as the main tools involved, tcpdump and …

Percona announces the release of Percona Server 5.6.32-78.0 on August 22nd, 2016. Download the latest version from the Percona web site or the Percona Software Repositories.

Based on MySQL 5.6.32, including all the bug fixes in it, Percona Server 5.6.32-78.0 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source and free – this is the …

In this post, we’ll look at a scalability fix for issues the query rewrite plugin had on performance.

Several months ago, Vadim blogged about the impact of a query rewrite plugin on performance. We decided to re-evaluate the latest release of 5.7(5.7.14), which includes fixes for this issue.

I reran tests for MySQL 5.7.13 and 5.7.14 using the same setup and the same test: sysbench OLTP_RO without and with the query rewrite plugin enabled.

MySQL 5.7.14 performs much better, with almost no overhead. Let’s check PMP for these runs:

MySQL 5.7.13

206 …