Author - Sveta Smirnova

Why Optimization derived_merge can Break Your Queries

MySQL optimizer bugs

Lately, I worked on several queries which started returning wrong results after upgrading MySQL Server to version 5.7 The reason for the failure was derived merge optimization which is one of the default
optimizer_switch  options. Issues were solved, though at the price of performance, when we turned it
OFF . But, more importantly, we could […]

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Webinar 6/27: MySQL Troubleshooting Best Practices: Monitoring the Production Database Without Killing Performance

performance troubleshooting MySQL monitoring tools

Please join Percona’s Principal Support Escalation Specialist Sveta Smirnova as she presents Troubleshooting Best Practices: Monitoring the Production Database Without Killing Performance on Wednesday, June 27th at 11:00 AM PDT (UTC-7) / 2:00 PM EDT (UTC-4).
Register Now
 
During the MySQL Troubleshooting webinar series, I covered many monitoring and logging tools such as:

General, slow, audit, binary, error […]

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Call for Questions: Webinar with MySQL Benchmarking Experts

benchmarking request

If you attended my latest Troubleshooting MySQL Concurrency Issues with Load Testing Tools webinar you learned how I exploit benchmarking tools to replicate locking issues and crashes. But I told you nothing about proper use of these tools: for reliable benchmarks. I did not tell you that for a reason… I am just a […]

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Troubleshooting MySQL Concurrency Issues with Load Testing Tools Webinar: Q & A

MySQL Troubleshooting

In this blog, I will provide answers to the Q & A for the Troubleshooting MySQL Concurrency Issues with Load Testing Tools webinar.
First, I want to thank everybody for attending my May 23, 2018, webinar on troubleshooting tools for MySQL. The recording and slides for the webinar are available here. Below is the list […]

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MySQL Test Framework for Percona XtraDB Cluster

MySQL Test Framework

At my latest webinar “MySQL Test Framework (MTR) for Troubleshooting”, I received an interesting question about MTR test cases for Percona XtraDB Cluster (PXC). Particularly about testing SST and IST.
This post is intended to answer this question. It assumes you are familiar with MTR and can write tests for MySQL servers. If you are […]

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Webinar Wed, 5/23: Troubleshooting MySQL Concurrency Issues with Load Testing Tools

Benchmarking tools for troubleshooting

Please join Percona’s Principal Support Escalation Specialist, Sveta Smirnova, as she presents Troubleshooting MySQL Concurrency Issues with Load Testing Tools on Wednesday, May 23, 2018 at 11:00 AM PDT (UTC-7) / 2:00 PM EDT (UTC-4).
Register Now
 
Normally, we use benchmarking tools when we are developing applications. When applications are deployed, benchmarks tests are usually too late to […]

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Webinar Thursday, April 12, 2018: MySQL Test Framework for Troubleshooting

MySQL Testing Framework

Percona’s Principal Support Engineer, Sveta Smirnova presents the webinar MySQL Test Framework for Troubleshooting on April 12, 2018, at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4).
MySQL Test Framework (MTR) provides a unit test suite for MySQL. MySQL Server developers and contributors write the tests in the framework, and use them to ensure the build […]

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Performance Schema for MySQL Troubleshooting Webinar: Q & A

MySQL Troubleshooting

In this blog, I will provide answers to the Q & A for the Performance Schema for MySQL Troubleshooting webinar.
First, I want to thank everybody for attending my March 1, 2018, webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I was unable to answer […]

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Webinar Thursday March 29, 2018: Effective Testing for Live Applications

Testing for Live Applications

Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Effective Testing for Live Applications on March 29, 2018, at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4).
When an application is hit with trouble in a live production environment, it is often difficult to:

Repeat a problematic scenario without the risk of making […]

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ANALYZE TABLE Is No Longer a Blocking Operation

analyze table

In this post, I’ll discuss the fix for lp:1704195 (migrated to PS-2503), which prevents
ANALYZE TABLE from blocking all subsequent queries on the same table.
In November 2017, Percona released a fix for lp:1704195 (migrated to PS-2503), created by Laurynas Biveinis. The fix, included with Percona Server for MySQL since versions 5.6.38-83.0 and 5.7.20-18, stops
ANALYZE TABLE from invalidating […]

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