The idea of ACID transactions are a basic feature of SQL’s individual Data Manipulation Language (DML) commands, like the INSERT, UPDATE, and DELETE statements. Transactions across two or more tables are a natural extension of ACID compliance features provided by DML commands. However, they require a structured programming approach, like a store procedure or like API implemented in an imperative language.

Surprisingly, transaction management wasn’t covered well in Alan Beaulieu’s Learning SQL because he only provided pseudo code logic. While I thought troubleshoot some broken MySQL SQL/PSM logic would be a good learning experience for students, it wasn’t. So, I wrote this sample code to show how to achieve an all or nothing transaction across four tables.

The code for this example on transaction management lets you perform the important tasks necessary to effect transaction …

This brief summarises the proceedings and outcomes of the 2nd MyWebinar which was held on 13th February 2021 at Online Webinar. As part of our thought leadership webinar series, our latest hosting webinar Migrate your EOL MySQL Servers (seamless migration to MySQL group replication / InnoDB cluster)

We have conducted MyWebinar with a very positive response with the help of software like zoom hosting arrangement and YouTube streaming and commitment of our business team, We have easily planned the perfect broadcasting for all of the attendees.

Over 30+ people took part in our webinar on 13th Feb 2021, to learn MySQL EOL and upgrade path. The session “Migrate your EOL MySQL servers to HA Complaint GR Cluster / InnoDB Cluster With Zero Downtime” by  …

Somebody asked me about how they could convert an XML file to a CSV file to upload into MySQL. They were asking the question based on an old Convert XML to CSV blog post from 2008. Amazing though that is, I had to explain the process no longer requires manual tasks, like calling Java files from the Apache XML Project. All they needed to do was use the Oxygen XML Editor, which is why I wrote this blog post.

For example, I had them use the same sample XML file from the old blog post (shown below) with one change. The encoding value needs to change from latin1 (ISO-8859-1) to unicode (UTF-8). Then, they should put it into a local Windows directory (mine went into the …

From MySQL 5.7, we had a Multi-threaded Slave (MTS) Applier mechanism called LOGICAL_CLOCK to overcome the problems of parallel replication within a database.

To further improve the parallelisation mechanism, from MySQL 8 (5.7.22) we have write-set replication, so before going further , lets look at the difference between Logical clock (LC) and Writeset.

LOGICAL_CLOCK

Transactions that are part of the same binary log group commit on a master are applied in parallel on a slave. The dependencies between transactions are tracked based on their timestamps to provide additional parallelisation where possible.

WRITESET

Write-set is a mechanism to track independent transactions that can be executed in parallel in the slave. Parallelising on write sets has potentially much more parallelism than logical_clock ,since it does not depend …

While you can download MySQL as a DMG package, a number of users would prefer to install it as a Docker instance. You won’t find the macOS downloads on the same web site as other downloads. You can use the following macOS download site.

After installing Docker on your macOS, you can pull a copy of the current MySQL Server with the following command:

docker pull mysql/mysql-server

You should create a mysql directory inside your ~/Documents directory with this command:

mkdir ~/Documents/mysql

Then, you should use the cd command to change into the ~/Documents/mysql directory and run this command:

pwd

It should return the following directory: …

While I thought my instructions were clear, it appears there should have been more in my examples for using the MySQL MSI. A key thing that happened is that students opted not to install:

Samples and Examples 8.0.22

Unfortunately, they may not have read the Preface of Alan Beaulieu’s Learning SQL, 3rd Edition where he explains how to manually download the files from the MySQL web site. Here are those, very clear, instructions (pg. XV) with my additions in italics for the MySQL Shell:

First, you will need to launch the mysql command-line client or the mysqlsh command-line shell, and provide a password, and then perform the following steps:

1. Go to https://dev.mysql.com/doc/index-other.html and download the files for the …

I’m switching to MySQL and leveraging Alan Beaulieu’s Learning SQL as a supporting reference for my Database Design and Development course. While reviewing Alan’s Chapter 5: Querying Multiple Tables, I found his coverage of using self-joins minimal.

In fact, he adds a prequel_film_id column to the film table in the sakila database and then a single row to demonstrate a minimal self-join query. I wanted to show them how to view a series of rows interconnected by a self-join, like the following:

SELECT   f.title AS film
,        fp.title AS prequel
FROM     film f LEFT JOIN film fp
ON       f.prequel_id = fp.film_id
WHERE    f.series_name = 'Harry Potter'
AND      fp.series_name = 'Harry Potter'
ORDER BY f.series_number;

It returns the following result set:

 …

Having recently installed a fresh copy of MySQL 8.0.21 on Windows, I took careful note of parsing changes in the MySQL Shell. It was tedious that we lost multiple statement processing, which is supported in the MySQL Client and MySQL Workbench because it uses MySQL Client.

It was frustrating when I subsequently discovered that the MySQL Shell took away the ability to write log files by removing the TEE and NOTEE commands. I suspected that since MySQL Workbench was still using the MySQL Client that it should be in the code tree. In fact, the mysql.exe client is in this directory:

C:\Program Files\MySQL\MySQL Server 8.0\bin

So, I immediately created a batch file to put the MySQL Client into my %PATH% environment variable when needed. I used this time tested DOS command: …

I’m glad that testing new MySQL releases is so frequent for me. Each testing cycle let me catch warning messages about deprecated behaviors before they’re removed. This one announced the deprecation of digits for floating point data types, like double. The following column definition for a table in my code tree triggered the warning message:

, amount                DOUBLE(10,2)

MySQL 8 (8.0.21) raised the following warning message:

Warning (code 1681): Specifying number of digits for floating point data types is deprecated and will be removed in a future release.

Recognizing the deprecation, I redefined the column as:

, amount                DOUBLE

I’m glad the MySQL development team is focused on alerting us to deprecations through warning messages. Naturally, I fixed all of …

MySQL 8.0 Performance Benchmarking on Amazon EC2 The scope of performance benchmarking

The core objective of this benchmarking exercise is to measure MySQL 8.0 performance, This include INSERTs , SELECTs and complex transaction processing (both INSERTs and SELECTs) without any tuning of MySQL 8 instance’s my.cnf. We agree tuning my.cnf will greatly improve performance but in this activity we wanted to benchmark MySQL 8 transaction processing capabilities and technically in MinervaDB we measure performance by Response Time and believe you can build high performance MySQL applications by writing optimal SQL. We have used Sysbench (https://github.com/MinervaDB/MinervaDB-Sysbench release 1.0.20) for this benchmarking activity. This is not a paid / sponsored benchmarking effort by any of the software or hardware vendors, We will remain …