Narrowing down which queries to optimize is a step in database administration that is often skipped - however it shouldn't be!  

Why is selecting the right queries to optimize so important? There are several reasons. 

Penny-Wise, Pound-Foolish  Look at the forest, not just the trees, and optimize globally, not locally. If you’re optimizing a query that never causes a user-visible problem, doesn’t impact other queries, and doesn’t significantly load servers, you might be “optimizing” things that don’t matter, spending more money than you save. Your time has value, too! Keep in mind, too, that optimizing a query that generates only 1% of the database’s overall load will not be a significant benefit to the bottom line.   Whack-A-Mole Queries It’s very common to  find a slow query in a log file, try re-executing it and  then find that it is fast. …

Join Percona’s Chief Evangelist, Colin Charles as he presents Differences Between MariaDB and MySQL on Wednesday, January 24, 2018, at 7:00 am PST (UTC -8) / 10:00 am EST (UTC -5).

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Tags: MariaDB, MySQL, Percona Server for MySQL, DBA, SysAdmin, DevOps
Experience Level: Novice

MariaDB and MySQL. Are they syntactically similar? Where do these two query languages differ? Why would I use one over the other?

MariaDB is on the path of gradually diverging from MySQL. One obvious example is the internal data …

Join Percona’s Product Manager Michael Coburn as he presents MySQL Troubleshooting and Performance Optimization with Percona Monitoring and Management (PMM) Part 2 on Thursday, January 18, 2018, at 11:00 am PST / 2:00 pm EST (UTC-8).

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Tags: Percona Monitoring and Management, PMM, Monitoring, MySQL, Performance, Optimization, DBA, SysAdmin, DevOps
Experience Level: Expert

Optimizing MySQL performance and troubleshooting MySQL problems are two of the most critical and challenging tasks for …

Thank you for attending my webinar on Wednesday, December 20, 2017, InnoDB Performance Optimization. In this blog, I will provide answers to the Q & A for the webinar.

Are the T2 CPUs similar to the M4 series?

I would expect them to be similar. Amazon does not disclose what specific version of CPUs they use for T2 instances. More details are available here.

Delay in spinlock code is pretty old code. Need to optimize based on today’s CPU? Your views?

There have been a number of improvements to the InnoDB Spinlock code during the last few years. For example, using CPU …

The website or mobile app is the storefront for participating in the modern digital era. It’s your portal for inviting users to come and survey your products and services. Much attention focuses on front-end development; this is where the HMTL5, CSS, and JavaScript are coded to develop the landing page that everyone sees when they visit your site.

But the real magic happens on the backend. This is the ecosystem that really powers your website. One writer has articulated this point very nicely as follows:

The technology and programming that “power” a site—what your end user doesn’t see but what makes the site run—is called the back end. Consisting of the server, the database, and the server-side applications, it’s the behind-the-scenes functionality—the brain of a site. …

As part of our support services, we do a lot of query optimization. This is where most performance gains come from. Here’s an example of the work we do.

Some days ago a customer arrived with the following table:

CREATE TABLE `infamous_table` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `member_id` int(11) NOT NULL DEFAULT '0',
  `email` varchar(200) NOT NULL DEFAULT '',
  `msg_type` varchar(255) NOT NULL DEFAULT '',
  `t2send` int(11) NOT NULL DEFAULT '0',
  `flag` char(1) NOT NULL DEFAULT '',
  `sent` varchar(100) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`),
  KEY `f` (`flag`),
  KEY `email` (`email`),
  KEY `msg_type` (`msg_type`(5)),
  KEY `t_msg` (`t2send`,`msg_type`(5))
) ENGINE=InnoDB DEFAULT CHARSET=latin1

And a query that looked like this:

SELECT COUNT(*)
  FROM `infamous_table`
 WHERE `t2send` > 1234
   AND …

Sometimes we are not sure if the database design we have created and our site has been using is correct and optimised. We all do have this feeling at times don't we :)


Well, MySQL provides with PROCEDURE ANALYSE() to help us detect inconsistencies in our database design by suggesting for an optimal datatype and data length for columns.

The syntax for using PROCEDURE ANALYSE() is as below:

SELECT ... FROM ... WHERE ... PROCEDURE
ANALYSE([max_elements,[max_memory]])

Ref: …

Welcome to another post in the series of Percona Live featured tutorial speakers blogs! In these blogs, we’ll highlight some of the tutorial speakers that will be at this year’s Percona Live conference. We’ll also discuss how these tutorials can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured tutorial, we’ll meet Øystein Grøvlen, Senior Principal Software Engineer at Oracle. His tutorial is on How to Analyze and Tune MySQL Queries for Better Performance. SQL query …

Very often MySQL is much less stable than we realize. In this video I explain how to detect and dianose these MySQL stalls that last for 5-10 seconds or more.

The reason nobody knows about these issues is that they’re:
a) rare
b) intermittent
c) monitoring software can’t catch them

You can use pt-stalk to detect and diagnose such issues. All of the tools I have mentioned in this video are part of Percona Toolkit (no wonder they all start with PT), you can find the toolkit here:

Percona Toolkit

Here’s the main commands I have discussed in this video:

Starting pt-stalk in foreground

# pt-stalk

Starting pt-stalk in background with email notification:

# pt-stalk …

When your car doesn’t start, you don’t just blindly change the battery, starter, fuel pump, spark plugs or all of the above. Instead, you go to your mechanic and ask him to check what is wrong (or you check it yourself if you are the mechanic) and then fix whatever is broken.

Yet very often I see DBAs doing exactly the opposite with their MySQL servers. Rather than assessing what is the server so busy with, they keep changing configuration options until the problem “goes away”. Alternatively, they add more RAM, more CPUs or faster disks, depending on which resources seems to be the most busy at a time. Or they switch to a new server altogether.

MySQL (with a help of some tools) has a really convenient way to analyse the workload and see clearly what exactly is MySQL so busy doing. And even how much improvement you can expect by, say, fixing a specific MySQL query.

…