Don’t Try This at Home!

Disclaimer: The procedure described in this blog post is not officially supported by Percona XtraBackup. Use it under your responsibility. I tested and used it successfully, but your mileage may vary.

Note from the author: Wikipedia defines clickbait as text (or a link) that is designed to attract attention and to entice users to read that online content, with a defining characteristic of being deceptive. Maybe the headline of this post is a bit deceptive, as there is no Percona XtraBackup for Windows, but I hope you will not feel deceived after reading this blog post, I just felt that it was funny to use a clickbait-style while writing it.

He Couldn’t Believe it When He Read That Post!

Pep had to migrate a client database from Windows to Linux …

MySQL 8.0.23 introduces a new feature that makes replication possible from a source server that has been configured without Global Transaction Identifiers (GTIDs) to a replica server configured with GTIDs. This can be achieved by configuring replication channels to use the parameter ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS with the CHANGE REPLICATION SOURCE command.…

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Microsoft Visual Studio plugins continuously compete to empower users with extended capabilities. Free tools have the most obvious advantage — while you don’t have to pay for them, they tend to deliver all the essentials to cover your basic needs. Paid tools mean broader functionality, convenience, and customization, but the bottom line is whether the […]

The post MySQL for Visual Studio vs dbForge Fusion for MySQL: A Comparison of Plugins appeared first on Devart Blog.

Just a quick how-to, to download, compile and use Sysbench on your RHEL/OL Linux box to test MySQL Server (note: compiling and using Sysbench is no mistery, the README file has all the instructions clearly explained, but I write this little guide to setup and use this tool in minutes).

Download and compile

The repository is hosted at: https://github.com/akopytov/sysbench. You can choose to download the latest master branch as usual or the latest stable. I have picked the latest stable. In order to compile and use certain MySQL library version, make sure mysql_config (used by sysbench auto configure to determine what libraries must be used) and a whole MySQL distribution is installed and/ or in the PATH.

If you have MySQL headers and libraries in non-standard locations (and no …

This quickstart shows you how to use the Azure portal to deploy a dedicated Percona Server for MySQL 8.0 drop-in replacement for MySQL that provides superior performance, scalability, and instrumentation. It also shows you how to connect to the server.

Prerequisites

Existing Azure subscription. If you don’t have a subscription, create a free Azure account before starting.

Create Percona Server for MySQL 8.0 Azure Instance

1. Go to the Azure portal to create a MySQL database using Percona Server for MySQL 8.0 image. Search for and select Percona Server for MySQL 8.0:
2. On the Percona Server for MySQL 8.0 page, press Create:
…

Interesting questions always come via my students. For example, “Why does the selective aggregation sample return null values as totals from the SUM() function in MySQL?”

First, here’s the code to build the sample table for the problem:

DROP TABLE IF EXISTS transaction;
CREATE TABLE transaction
( transaction_id      int unsigned primary key auto_increment
, transaction_date    date
, transaction_amount  double );

INSERT INTO transaction
( transaction_date, transaction_amount )
VALUES
 ('2021-01-10', 56)
,('2021-02-14',23.02)
,('2021-03-31',31.06)
,('2021-01-01',.25)
,('2020-01-02', 52)
,('2020-02-08',22.02)
,('2020-03-26',32.06)
,('2020-01-12',.75);;

Now, here’s the selective aggregation query:

SELECT   EXTRACT(YEAR FROM transaction_date) AS "Year"
,        SUM(
           CASE
             WHEN EXTRACT(MONTH FROM transaction_date) = 1 THEN transaction_amount
            END) AS "Jan"
,        SUM( …

For performance, having a warm InnoDB Buffer Pool is very important. What does that mean ?

A warm buffer pool means that the most used pages (working set) required by the production workload are already loaded in memory (in the buffer pool). If so, MySQL doesn’t need to read the pages from disk every time it requires the most used page and speeds up the process when the needed data is already in memory.

When you start MySQL, by default the InnoDB Buffer Pool is cold and the warm up process can even take days sometimes…

So, you can already deduce that restarting mysqld is a source of having a cold Buffer Pool as it will start empty. Another reason to have a non optimal Buffer Pool is to load it unnecessary pages. This can happen during a logical dump or load. If you regularly do a mysqldump for example (don’t forget that MySQL Shell dump & load is better if you do logical dumps, but introduces also the …

Starting with the release of proxysql-admin 2.0.15,  the proxysql-admin 2.x series can now encrypt the credentials needed to access proxysql and cluster nodes. This only applies to the proxysql-admin configuration, this does not change the ProxySQL config, so those credentials are still unencrypted.

The credentials file is the unencrypted file containing the usernames, passwords, hostnames, and ports needed to connect to ProxySQL and PXC (Percona XtraDB Cluster).

The proxysql-login-file tool is used to encrypt the credentials file. This encrypted file is known as a login-file. This login-file can then be used by the proxysql-admin and proxysql-status scripts.

Note: This feature requires OpenSSL v1.1.1 and above (with the exception of Ubuntu 16.04). Please see the …

In my talk at Percona Live 2021, “Creating Chaos in Databases”, I discussed how creating a controlled interruption in available resources (I used primary pod and network interruptions) allows us to test the stability of a database, and in our case, Percona XtraDB Cluster.

I also mentioned in the talk that my testing led to diagnosing a few unpleasant bugs, namely:

• PXC-3437: Node fails to join in the endless loop
• PXC-3580: Aggressive network outages on one node makes the whole cluster unusable
• …

I recently learned of some odd behavior using MySQL BETWEEN operator queries, filtering by a DATETIME column. I wrote about this over on Medium so I am sharing the post for any readers here who are interested…

Image by _Alicja_ from Pixabay 

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If you enjoy the content written here, by all means, share this blog and your favorite post(s) with others who may benefit …