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Another Hanging Query

You are a DBA, enjoying a good read about the MySQL 8.0.1 development milestone release which contains CTEs.  And, window functions are coming in 8.0.2. Perhaps, you think, the analytics team could make good use of window functions to perform rankings on the sales of products compared to the average sales for all the products.

Dreaming about the possibility of trying CTEs in 8.0.1, you get a phone from a user complaining that her ‘SELECT’ statement has been running for a long time.

Fortunately, you have the MySQL Enterprise Monitor (MEM) which is part of the MySQL Cloud Service (MySQLCS).  You have recently set up your MySQL database in MySQLCS where you have installed MEM.

You login to your identity domain in MySQLCS and select you service and click the pull-down menu choice ‘Enterprise Monitor URL’:

After logging in, you notice on the MEM dashboard that there is a spike in database activity …

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Reset root password on Galera Cluster (Percona or MariaDB)

Reset MySQL root password for Galera Cluster ( Percona Xtradb / MariaDB )

A practical explanation: problems during unicode collation conversion

Introduction

Recently I have been involved in an effort to convert MySQL databases from a utf8 character set to utf8mb4. As a part of this effort, my team evaluated which collations would be best for facilitating a broad range of multi-lingual support.

There have been many recent posts in the MySQL community about better unicode collation support in MySQL 8 such as from the MySQL Server Team’s blog at Oracle, who have also done a good job of showing us how newer collations based on UTF8 9.0.0 will properly group and sort characters according to their case and inheritance. As the title of the latter post suggests, the “devil is” indeed “in the details”.

There is also the matter of the …

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MySQL Workbench 6.3.9 GA has been released

Dear MySQL users,

The MySQL developer tools team announces 6.3.9 as our GA release for
MySQL Workbench 6.3.

For the full list of changes in this revision, visit
http://dev.mysql.com/doc/relnotes/workbench/en/changes-6-3.html

For discussion, join the MySQL Workbench Forums:
http://forums.mysql.com/index.php?152

Download MySQL Workbench 6.3.9 GA now, for Windows, Mac OS X 10.10+,
Oracle Linux 7, Fedora 24 and 25, Ubuntu 16.04 and 16.10
or sources, from:

http://dev.mysql.com/downloads/tools/workbench/

20 Common Performance_schema FAQs

1.What are the different types of tables ?

Current/Summary/History/

Setup tables:
Setup_consumers
Setup_actors
Setup_instruments
………………….

Waits

| events_waits_current |
| events_waits_history |
| events_waits_history_long |
| events_waits_summary_by_account_by_event_name |
| events_waits_summary_by_host_by_event_name |
| events_waits_summary_by_instance |
| events_waits_summary_by_thread_by_event_name |
| events_waits_summary_by_user_by_event_name |
| events_waits_summary_global_by_event_name |

Statements

| events_statements_current |
| events_statements_history |
| events_statements_history_long |
| events_statements_summary_by_account_by_event_name |
| events_statements_summary_by_digest |
| events_statements_summary_by_host_by_event_name |

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Easy-to-use Perl scripts to backup your MySQL database with mysqldump and FTP the files to a remote server

Most users of MySQL utilize the mysqldump utility to backup their database. While mysqldump is handy and easy-to-use (and free), if you have data which is important to your business, then you should take a look at the MySQL Enterprise Edition – and use MySQL Enterprise Backup instead. The MySQL Enterprise Backup allows you to backup your database without the table locking you get with mysqldump. And, it is extremely fast – especially when you have to restore your database. Here is a sample speed comparison between MySQL Enterprise Backup and …

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The Hanging Query

You are a DBA working hard to keep all the databases running so your staff can enter key data.  Okay, if truth be known, maybe at the same time you are creating a MySQL program that fires off various lights with music for numerous holiday celebrations (Christmas, Day of the Return of the Wandering Goddess, Festivus, Hanukkah, Kwanzaa, Winter Solstice, Saturnalia, and Yule).

Suddenly, you get a dreaded phone from a harried user, ‘my query is hanging’. Time for you to drop everything else. Is the database down? Is there a networking problem? A bad index?

Fortunately, you have the MySQL Enterprise Monitor (MEM) to help you to solve the problem quickly. You notice on the MEM dashboard that there is a spike in the number of connections and you right-click, changing color to blue over the spike:

After right-clicking on the little disk by the query spike, you advance to the Query Analyzer panel where you see individual …

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The Hanging Query
Patching in the Cloud

As a developer at another company (not Oracle), I once worked the support phone lines as the philosophy of the company was that developers should be familiar with real customers and their applications. I recall one call on a particular morning:  a customer was crying because she had upgraded her database. The upgrade had destroyed her data. And, she had no backup. Her research data had been created for her PhD thesis. Sadly, she could not complete her degree since her work had been destroyed.

This true story has always reminded me of how deadly an upgrade can be.

Fortunately, the Oracle MySQL Cloud Service (MySQLCS) software has made the upgrade process more robust. With the MySQLCS software, you can test drive your upgrade process with your application. By spinning up a MySQLCS cloud instance you can:

  • Pre-check the new MySQL version to make sure system requirements such as disk space are adequate before the …
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MySQL Workbench 6.3.8 GA has been released

Dear MySQL users,

The MySQL developer tools team announces 6.3.8 as our GA release for
MySQL Workbench 6.3.

For the full list of changes in this revision, visit
http://dev.mysql.com/doc/relnotes/workbench/en/changes-6-3.html

For discussion, join the MySQL Workbench Forums:
http://forums.mysql.com/index.php?152

Download MySQL Workbench 6.3.8 GA now, for Windows, Mac OS X 10.9+,
Oracle Linux 6 and 7, Fedora 23 and Fedora 24, Ubuntu 16.04
or sources, from:

http://dev.mysql.com/downloads/tools/workbench/

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