by Peter Zaitsev | Jun 1, 2023 | Insight for Developers, MySQL
Updated June 1, 2023. Suboptimal MySQL ORDER BY implementation, especially together with MySQL LIMIT is often the cause of MySQL performance problems. Here is what you need to know about MySQL ORDER BY LIMIT optimization to avoid these problems. Try Now: Free your...
by Alok Pathak | Dec 16, 2015 | Insight for DBAs, MySQL
We work on data recoveries quite often. In many cases, we recover table structures from the .frm files because there was no backup available. There is already a great blog post by my colleague Miguel Ángel Nieto about how we can recover structures from .frm files...
by Bill Karwin | Jul 17, 2014 | Insight for Developers, MySQL, Webinars
On Wednesday I gave a presentation on “How to Avoid Even More Common (but Deadly) MySQL Development Mistakes” for Percona MySQL Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and...
by Yves Trudeau | May 23, 2014 | Benchmarks, Hardware and Storage, Insight for DBAs, MySQL, Percona Live
Update: do not do this, this has been proven to corrupt data! During April’s Percona Live MySQL Conference and Expo 2014, I attended a talk on MySQL 5.7 performance an scalability given by Dimitri Kravtchuk, the Oracle MySQL benchmark specialist. He mentioned at...
by Bill Karwin | Mar 7, 2014 | Insight for Developers, MySQL, Webinars
On Wednesday I gave a presentation on “How to Avoid Common (but Deadly) MySQL Development Mistakes” for Percona MySQL Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who...
by Bill Karwin | Feb 12, 2014 | Insight for DBAs, Webinars
January 22 I gave a presentation on “How to Avoid Common (but Deadly) MySQL Operations Mistakes” for Percona MySQL Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to...
by Bill Karwin | Jan 13, 2014 | Insight for DBAs, Insight for Developers, Webinars
On January 22 I’ll be presenting the first of a series of two new webinars focusing on avoiding common MySQL mistakes: How to Avoid Common (but Deadly) MySQL Operations Mistakes. “Don’t bother me with DBA ‘best practices,’ we have real work to get done.” So go...
by Stephane Combaudon | Dec 3, 2013 | Insight for DBAs, MySQL
INFORMATION_SCHEMA is usually the place to go when you want to get facts about a system (how many tables do we have? what are the 10 largest tables? What is data size and index size for table t?, etc). However it is also quite common that such queries are very slow...
by Bill Karwin | May 20, 2013 | MySQL, Webinars
Next Friday, May 31 at 10 a.m. Pacific, I’ll present Percona’s next webinar, “SQL Query Patterns, Optimized.” Based on my experiences solving tough SQL problems for Percona training and consulting, I’ll classify several common types of...
by Bill Karwin | Feb 18, 2013 | Insight for DBAs, MySQL, Percona Events, Percona Software
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 is being spent. This month we...
by Aurimas Mikalauskas | Jan 16, 2013 | MySQL
Queries in MySQL, Sphinx and many other database or search engines are typically single-threaded. That is when you issue a single query on your brand new r910 with 32 CPU cores and 16 disks, the maximum that is going to be used to process this query at any given point...
by Aurimas Mikalauskas | Jan 15, 2013 | Insight for Developers, MySQL
One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do...
by Aurimas Mikalauskas | Jan 9, 2013 | Insight for DBAs, MySQL
While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication...
by Stephane Combaudon | Jan 7, 2013 | MySQL
On January 16th at 10 AM Pacific/1 PM Eastern, I will give a webinar about the main traps that are awaiting you when designing and building a stable and high-performance MySQL application. I will discuss a broad range of topics, from hardware and backups to...
by Martin Arrieta | Jan 3, 2013 | Insight for DBAs, MySQL, Percona Software
pt-stalk recipes: Gather forensic data about MySQL when a server problem occurs It happens to us all from time to time: a server issue arises that leaves you scratching your head. That’s when Percona Toolkit’s pt-stalk comes into play, helping you diagnose...
by Aurimas Mikalauskas | Dec 20, 2012 | Cloud, Insight for DBAs, MySQL
We are doing a migration from Amazon RDS to EC2 with a customer. This, unfortunately, involves some downtime – if you are an RDS user, you probably know you can’t replicate an RDS instance to an external server (or even EC2). While it is annoying, this...
by Aurimas Mikalauskas | Aug 29, 2012 | Insight for DBAs, MySQL
If you ever had a replication slave that is severely behind, you probably noticed that it’s not catching up with a busy master at a steady pace. Instead, the “Seconds behind master” is going up and down so you can’t really tell whether the...
by Jay Janssen | Dec 16, 2011 | MySQL
There are about a gazillion FAQs and HOWTOs out there that talk about XFS configuration, RAID IO alignment, and mount point options. I wanted to try to put some of that information together in a condensed and simplified format that will work for the majority of use...
by Aurimas Mikalauskas | Apr 17, 2011 | Insight for DBAs, MySQL
I use Aspersa tools a lot and I find myself going to the website just to download one of the tools all the time. I love I can download maatkit with a simple wget maatkit.org/get/tool command so I made bit.ly shortcuts for all of the current aspersa tools. Here’s...
by Fernando Ipar | Apr 7, 2011 | Insight for Developers, MySQL
I recently worked on a customer case where at seemingly random times, inserts would fail with Innodb error 139. This is a rather simple problem, but due to it’s nature, it may only affect you after you already have a system running in production for a while....
