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Hidden Cost of Foreign Key Constraints in MySQL

Do you wonder if MySQL tells you the truth about writes to tables that have foreign key constraints? The situation is complex, and getting visibility on what is really happening can be a problem.

I found this issue intriguing and decided to share and highlight some examples.

Query Plan

Let us take this example table:

CREATE TABLE `product` (
  `category` int NOT NULL,
  `id` int NOT NULL,
  `price` decimal(10,0) DEFAULT NULL,
  PRIMARY KEY (`category`,`id`)
) ENGINE=InnoDB;

We want to know how costly an example UPDATE against this table will be:

mysql > EXPLAIN update product set id=id+1 where id=65032158 and category=3741760\G
*************************** 1. row ***************************
           id: 1
  select_type: UPDATE
        table: product
   partitions: NULL
         type: range
possible_keys: PRIMARY
          key: PRIMARY
      key_len: 8
          ref: const,const
         rows: 1 …
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MySQL SUBSTRING() Function With Examples – Substack Repost

It’s no secret that text or string data are one of the most common datatypes you will process. At times, only a specific portion of a string may be needed and this is the perfect use case for the SUBSTRING() character function…

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you subscribe to the OpenLampTech newsletter.

Recently, I published an article over on the OpenLampTech Substack publication page, MySQL SUBSTRING() Function – With Examples, where I cover syntax and examples of the function.

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Raspberry Pi Bullseye Percona Server 64bit

I love the Raspberry Pi, and I love Percona server. The combination of the two can provide a nice home database. I have been running a Percona Server database since 2019 to hold all the weather information, that I collect from several of my Weather Stations.

I did a my first blog post on installing Percona Server 5.7 on the Raspberry Pi 3+.

You can read that blog post here: How to Build a Percona Server “Stack” on a Raspberry Pi 3+

Fast forward to 2022 and we now have the resources to build Percona Server 8.0 64-bit on the Raspberry Pi. In this post I will cover building and installing Percona Server 8.0.29 and Percona XtraBackup 8.0.29.

Prereqs:

  1. Raspberry Pi 3B+, 4 or 400 (any memory size will work).
  2. 128GB or 256GB microSD card. Of course you can go …
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Ecopaynet Chooses MySQL HeatWave Over AWS for Performance and Price

  Many FinTech companies and financial institutions have selected MySQL to build modern applications. The performance, ease of use, and customer support from the MySQL team are some of the many reasons why financial institutions and FinTech companies choose to use MySQL. Ecopaynet is a FinTech company based in Spain. Ecopaynet services include electronic payment […]

Ecopaynet Chooses MySQL HeatWave Over AWS for Performance and Price

Ecopaynet's customer success story describes why they chose MySQL HeatWave over AWS to shorten their time to market and benefit from a better price-performance.

sysbench 1.1.0 rpm with SSL support

For a future article, I was again looking into the possibility of using sysbench to generate data and load on a MySQL database. However, I needed an SSL connection which only version 1.1.0 supports (see issue 308).

Alexey didn’t create a branch and/or release for the version 1.1.0. The code is the master branch.

As you know, I like to install software using the Operating System’s packaging and so I created a rpm for sysbench 1.1.0.

If you are also interested to use this version, here are the rpms for some popular OS and architecture (including Arm):

sysbench-1.1.0-1.fc35.x86_64

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OpenLampTech issue #20 – Substack Repost

This 20th issue of the OpenLampTech newsletter marks 5 continuous months of weekly publishing. Thank you, the readers, for making it possible and continuing to read these newsletters. Once again, this week’s issue has plenty of PHP/MySQL content so enjoy the newsletter!

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you subscribe to the OpenLampTech newsletter.

This week’s OpenLampTech newsletter issue has plenty to read for everyone as I am loading these newsletters up! We are looking at articles covering:

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MySQL CSV Output

Saturday, I posted how to use Microsoft ODBC DSN to connect to MySQL. Somebody didn’t like the fact that the PowerShell program failed to write a *.csv file to disk because the program used the Write-Host command to write to the content of the query to the console.

I thought that approach was a better as an example. However, it appears that it wasn’t because not everybody knows simple redirection. The original program can transfer the console output to a file, like:

powershell .\MySQLODBC.ps1 > output.csv

So, the first thing you need to do is add a parameter list, like:

param (
  [Parameter(Mandatory)][string]$fileName
)

Anyway, it’s trivial to demonstrate how to modify the PowerShell program to write to a disk. You should also create a virtual PowerShell drive before writing the file. That’s because you can change the physical directory anytime you want with minimal changes to rest of …

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Introduction to AWS MySQL Security on RDS : Network

Nowadays everything is getting digitalized and migration toward the cloud is at its peak. There is a high chance of data leaks if we don’t tighten the security of the Database servers. It is mandatory to secure the database by restricting access to Database. Although we have restricted the access. We need to monitor the activity of the user to prevent the unwanted usage of data.

Security will be split into three layers

  1. Network-level security.
  2. OS level security.
  3. Database level security.

OS level security will be handled by the AWS team. Since It is managed by the AWS Team. So all the security patching, minor version upgrades of OS, and kernel tuning will be governed by the AWS infra team.

Network-level security and database-level security are owned by the end user.

Security
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MySQL ODBC DSN

This post explains and demonstrates how to install, configure, and use the MySQL’s ODBC libraries and a DSN (Data Source Name) to connect your Microsoft PowerShell programs to a locally or remotely installed MySQL database. After you’ve installed the MySQL ODBC library, use Windows search field to find the ODBC Data Sources dialog and run it as administrator.

There are four steps to setup, test, and save your ODBC Data Source Name (DSN) for MySQL. You can click on the images on the right to launch them in a more readable format or simply read the instructions.

MySQL ODBC Setup Steps

  1. Click the SystemDSN tab to see he view which is …
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