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Displaying posts with tag: MySQL 8.0 (reset)
MySQL GTID: restore a master from a replica’s backup

To avoid infinite replication loops MySQL doesn’t allow you to have log_slave_updates and replicate-same-server-id.

When using GTIDs that may lead to something not expected that you may not be aware of.

In this scenario, we have 2 MySQL servers using GTID. The sever uuid part of the GTID has been modified in the illustration to make it more clear. Both servers have log_slave_updates enabled too:

So far nothing unusual. So let’s write data on the master (MySQL A):

We can see that this first …

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Back Up MySQL View Definitions

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If you want to back up your table and views, stored procedures, or stored function definitions, you can use mysqldump or mysqlpump to export the schema without the data. However, if you just want the views you need to look for another option. This blog shows how MySQL Shell comes to the rescue.

Backup the view definition using MySQL Shell

There are a couple of approaches to get the view definitions. One option is to consider the information_schema.VIEWS view which has the following columns:

mysql> SELECT COLUMN_NAME AS Field, COLUMN_TYPE AS Type
         FROM information_schema.COLUMNS
        WHERE TABLE_SCHEMA = 'information_schema'
              AND TABLE_NAME = 'VIEWS'
        ORDER BY ORDINAL_POSITION; …
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Upgrading from MySQL 5.7 to 8.0 on Windows

As you may know, I’m using MySQL exclusively on GNU/Linux. To be honest for me it’s almos 20 years that the year of Linux on the desktop happened. And I’m very happy with that.

But this week-end, I got a comment on an previous post about upgrading to MySQL 8.0, asking how to proceed on Windows. And in fact, I had no idea !

So I spent some time to install a Windows VM and for the very first time, MySQL on Windows !

The goal was to describe how to upgrade from MySQL 5.7 to MySQL 8.0.

So once MySQL 5.7 was installed (using MySQL Installer), I created some data using MySQL Shell:

Of course I used latest MySQL Shell, 8.0.18 in this case. Don’t forget that if you are using MySQL Shell or MySQL Router, you must always use the latest …

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pre-FOSDEM MySQL Days 2020: registration is now open !

Hello dear MySQL Community ! As you know FOSDEM 2020 will take place February 1st and 2nd. After having received many, many requests we decided to organize for the 4th year in a row the pre-FOSDEM MySQL Day… with a big change, for this edition the event will be called “pre-FOSDEM MySQL Days” !

We have decided to extend that extra day related to the world’s most popular open source database to 2 days: 30th and 31st of January at the usual location in Brussels.

We will also have the usual sessions track but most probably a second room for those who would like to get their hands dirty in the code !!

Please don’t forget to register as soon as possible as you may already know, the seats are limited !

Register on eventbrite: …

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MySQL Shell Plugins: InnoDB

Today, we will cover a totally different MySQL Shell plugin: InnoDB.

Currently only 3 methods have been created:

Those related to the Table space fragmentation, have already been covered in this recent article.

Let’s discover the getAlterProgress()method. This method allows us to have an overview of the progress of some alter statements status like:

  • stage/innodb/alter table (end)
  • stage/innodb/alter table (flush)
  • stage/innodb/alter table (insert)
  • stage/innodb/alter table (log apply index)
  • stage/innodb/alter table (log apply table)
  • stage/innodb/alter table (merge sort)
  • stage/innodb/alter table (read PK and internal sort)
  • stage/innodb/alter tablespace (encryption)

This is an output of the method:

As …

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MySQL Shell Plugins: check (part 3)

What is great with MySQL Shell Plugins, it’s that it provides you an infinite amount of possibilities. While I was writing the part I and part II of the check plugin, I realized I could extend it event more.

The new methods I added to the plugin are especially useful when you are considering to use MySQL InnoDB Cluster in Multi-Primary mode, but not only

Let’s have a look at these new methods:

These 4 new methods are targeting large queries or large transactions. It’s also possible to get the eventual hot spots.

Let’s see the first two that are more basic in action:

The first method …

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MySQL Shell Plugins: check (part 2)

In the first part of this article related to the check plugin, we discovered information retrieved from the binary logs. This part, is about what Performance_Schema and SYS can provide us about the queries hitting the MySQL database.

Currently, 3 methods are available:

  • getSlowerQuery()
  • getQueryTempDisk()
  • getFullTableScanQuery()

The method’s name should be self explaining.

This is an overview of the parameters for each methods:

ext.check.getSlowQuery()ext.check.getQueryTempDisk()ext.check.getFullTableScanQuery()

Some methods allow a select parameter if only SELECT statements should be returned.

When only one query is returned (default), it’s also possible to …

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MySQL: Check who’s trying to access data they should not

To illustrate how easy it’s to see who’s trying to access data they have not been granted for, we will first create a schema with two tables:

mysql> create database mydata;
mysql> use mydata
mysql> create table table1 (id int auto_increment primary key, 
              name varchar(20), something varchar(20));
mysql> create table table2 (id int auto_increment primary key, 
              name varchar(20), something varchar(20));

Now, let’s create a user :

mysql> create user myuser identified by 'mypassword';

And as it’s always good to talk about SQL ROLES, let’s define 3 roles for our user:

  • myrole1: user has access to both tables in their entirety, reads and writes
  • myrole2: user has access only to `table2`, reads and writes
  • myrole3: user has only access to the column `name`of `table1` and …
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MySQL Clone Plugin Speed Test

In my previous blog, I have explained how the MySQL clone plugin works internally. In this blog, I am going to do a comparison of  Backup and Recovery speed of MySQL clone plugin with other available mysql open source backup tools.

Below tools are used for speed comparison of Backup and Recovery,

  1. Clone-Plugin
  2. Xtrabackup
  3. mysqldump
  4. mydumper with myloader
  5. mysqlpump

Test …

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Using MySQL Community Repository with OL 8/RHEL 8/CentOS 8

MySQL 8.0 is now part of RedHat Enterprise 8 and other distros based on it like CentOS and Oracle Linux.. This is a very good thing !

However if for any reason you want to use the latest version of MySQL from the Community Repository, you may encounter some frustration if you are not familiar with the new way the package manager works.

Let’s start by verifying our system:

LSB Version:    :core-4.1-amd64:core-4.1-noarch
Distributor ID:    OracleServer
Description:    Oracle Linux Server release 8.0
Release:    8.0
Codename:    n/a

We can see that we are on Oracle Linux 8.0. So now let’s try to install MySQL Server:

[root@localhost ~]# dnf install mysql-server
Last metadata expiration check: 0:08:15 ago on Sat 02 Nov 2019 09:54:07 AM UTC.
Dependencies resolved.
============================================================================================
  Package                 Arch   Version …
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