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Displaying posts with tag: troubleshooting (reset)
Troubleshooting MySQL access privileges issues: Q & A

In this blog, I will provide answers to the Q & A for the Troubleshooting MySQL Access Privileges Issues webinar.

First, I want to thank everybody for attending the February 23 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: Should the root@localhost user be given ALL privileges or Super privileges? Does All include Super privileges also?

A: Yes, you should have a user with all privileges. Better if …

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Webinar Thursday, February 23, 2017: Troubleshooting MySQL Access Privileges Issues

Please join Sveta Smirnova, Percona’s Principal Technical Services Engineer, as she presents Troubleshooting MySQL Access Privileges Issues on
February 23, 2017 at 11:00 am PST / 2:00 pm EST (UTC-8).

Do you have registered users who can’t connect to the MySQL server? Strangers modifying data to which they shouldn’t have access?

MySQL supports a rich set of user privilege options and allows you to fine tune access to every object in the server. The latest versions support authentication plugins that help to create more access patterns.

However, finding errors in …

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MySQL Bug 72804 Workaround: “BINLOG statement can no longer be used to apply query events”

In this blog post, we’ll look at a workaround for MySQL bug 72804.

Recently I worked on a ticket where a customer performed a point-in-time recovery PITR using a large set of binary logs. Normally we handle this by applying the last backup, then re-applying all binary logs created since the last backup. In the middle of the procedure, their new server crashed. We identified the binary log position and tried to restart the PITR from there. However, using the option

--start-position

, the restore failed with the error “The BINLOG statement of type Table_map was not preceded by a format description BINLOG statement.” This is a known bug and is reported as MySQL …

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MySQL Replication Troubleshooting: Q & A

In this blog, I will provide answers to the Q & A for the MySQL Replication Troubleshooting webinar.

First, I want to thank everybody for attending the August 25 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: Hi Sveta. One question: how is it possible to get N previous events using the SHOW BINLOG EVENTS command? For example, the position is 999 and I want to analyze the previous five events. Is it possible?

A: Not, there is no such option. You cannot get the previous five events using

SHOW BINLOG EVENTS

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InnoDB Troubleshooting: Q & A

In this blog, I will provide answers to the Q & A for the InnoDB Troubleshooting webinar.

First, I want to thank everybody for attending the August 11 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: What’s a good speed for buffer pool speed/size for maximum query performance?

A: I am sorry, I don’t quite understand the question. InnoDB buffer pool is an in-memory buffer. In an ideal case, your whole active dataset (rows that are accessed by application regularly) should be in the buffer pool. There is a good …

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Webinar Thursday May 26: Troubleshooting MySQL hardware resource usage

Join Sveta on Thursday, May 26, 2016, at 10 am PDT (UTC-7) for her webinar Troubleshooting MySQL hardware resource usage.

MySQL does not just run on its own. It stores data on disk, and stores data and temporarily results in memory. It uses CPU resources to perform operations, and a network to communicate with its clients.

In this webinar, we’ll discuss common resource usage issues, how they affect MySQL Server performance, and methods to find out how resources are being used. We will employ both OS-level tools, and new features in Performance Schema that provide detailed information on what exactly is happening inside MySQL Server.

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Introduction to Troubleshooting Performance – Troubleshooting Slow Queries webinar: Q & A

In this blog, I will provide answers to the Q & A for the Troubleshooting Slow Queries webinar.

First, I want to thank you for attending the April 28 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: I’ve heard that is a bad idea to use

select *

; what do you recommend?

A: When I used

SELECT *

 in my slides, I wanted to underline the idea that sometimes you need to select all columns …

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Webinar Q & A for Introduction to Troubleshooting Performance: What Affects Query Execution?

In this blog, I will provide answers to the Webinar Q & A for Introduction to Troubleshooting Performance: What Affects Query Execution?

First, I want to thank you for attending the April, 7 webinar. This webinar is the third in the “MySQL Troubleshooting” webinar series and last introductory webinar in the series. The recording and slides for the webinar are available here. Here is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: If we had some MyISAM tables, could we use …

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Troubleshooting MySQL Performance. Step Zero: Check If You Have a Performance Problem to Troubleshoot

I lost count of the number of times I had customers come to me for a regular MySQL performance check-up saying “no, we don’t have any performance problems right now”, just to find they do actually have them, they’re just not aware of it. It’s no big surprise this happens when you’re not using your system as actively as your users are.

So let me share with you one trick I’m using to quickly check if the system I’m on has any problems that need troubleshooting. Actually, it’s dead simple. And no, it’s not a slow query log, it’s Threads_running. Let me show you.

Wait, what’s wrong with the slow query log?

Nothing at all. MySQL’s slow query log is a great tool when you’re looking for slow queries. Or when you’re fishing for things to optimize – either to reduce the resource consumption, or to increase speed for queries you didn’t know are slow.

And it’s …

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MySQL 5.7.6 is out. Be prepared for big changes



Today Oracle released MySQL 5.7.6 milestone 16. With this, MySQL 5.7 has been in development for over 2 years.
Compared to MySQL 5.6, the changes are quite extensive. The main effort of the team has been focused on speed, with performance reportedly improved from 2 to 3 times compared to previous releases.
A full list of what is new would take too much space here, but I would like to mention some key points:


  • Oracle has spent a considerable amount of energy in the improvement of MySQL security and safety. You will see many new features, but even more old features that were deprecated and more that were removed after deprecation in 5.6.
  • The installation process has been changing in every …
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