Many of my students wanted to know how to write a simple PSM (Persistent Stored Module) for MySQL that saved the writes to all table as a group. So, to that end here’s simple example.

1. Create four sample tables in a re-runnable script file:

   /* Drop and create four tables. */
   DROP TABLE IF EXISTS one, two, three, four;
   CREATE TABLE one   ( id int primary key auto_increment, msg varchar(10));
   CREATE TABLE two   ( id int primary key auto_increment, msg varchar(10));
   CREATE TABLE three ( id int primary key auto_increment, msg varchar(10));
   CREATE TABLE four  ( id int primary key auto_increment, msg varchar(10));
   

2. Create a locking PSM across the four tables:

   /* Conditionally drop procedure. */
   DROP PROCEDURE IF EXISTS locking;
   
   /* Set delimiter to $$ to allow ; inside the procedure. */
   DELIMITER $$
   
   /* Create a transaction procedure. */
   CREATE PROCEDURE locking(IN pv_one   varchar(10)
                           ,IN pv_two …

The AWS ledger database (QLDB) is an auditors best friend and lives up to the stated description of “Amazon QLDB can be used to track each and every application data change and maintains a complete and verifiable history of changes over time.”

This presentation will go over what was done to take a MySQL application that provided auditing activity changes for key data, and how it is being migrated to QLDB.

While QLDB does use a SQL-format for DML (PartiQL), and you can perform the traditional INSERT/UPDATE/DELETE/SELECT, the ability to extend these statements to manipulate Amazon Ion data (a superset of JSON) gives you improved capabilities and statements.

Get a comparison of how to map a MySQL structure multiple tables and lots of columns into a …

The RDS Aurora MySQL/PostgreSQL capabilities of AWS extend the High Availability (HA) capabilities of RDS read replicas and Multi-AZ. In this presentation I discuss the different capabilities and HA configurations with RDS Aurora including:

• RDS Aurora Cluster single instance
• RDS Aurora Cluster multiple instances (writer + 1 or more readers)
• RDS Aurora Cluster multi-master
• RDS Aurora Global Cluster
• RDS Aurora Cluster options for multi-regions

Each option has its relative merits and limitations. Each will depend on your business requirements, global needs and budget.

• Presented at Percona Live Online 2021
• …

MySQL Server offers, among the different security features, encryption at rest (or Transparent Data Encryption, TDE) in the commercial release (find the differences with Community here).

While testing TDE with MySQL InnoDB Cluster, I was wondering what inner mechanism was implemented to deal with TDE, master keys and keyrings, and the clone plugin. If I need to clone an instance, how would everything work so to guarantee my InnoDB Cluster instances will still be encrypted, and the keyring chosen would still use a good master key to decrypt tablespace keys and finally tablespace pages?

The answer is obviously that this is fully managed. You can add instances to …

During many decision-making phases in programming code (conditional logic), there are times execution depends on several different factors. Multiple conditional tests are powerful and constraining, oftentimes requiring more than one test to be passed in order for program flow to proceed. For MySQL (and standard SQL in general) the CASE expression is used for IF/THEN/ELSE conditional logic. The post, MySQL Simple CASE Expression – with examples, covered Simple CASE queries which are essentially equality tests. MySQL Simple CASE is but one variant of 2, with the other being a MySQL Searched CASE Expression.  A MySQL Searched CASE Expression can have multiple conditional tests in each WHEN …

We are pleased to announce the release of MySQL Cluster 8.0.25. MySQL Cluster is the distributed, shared-nothing variant of MySQL. This storage engine provides: In-Memory storage – Real-time performance (with optional checkpointing to disk) Transparent Auto-Sharding – Read & write scalability Active-Active/Multi-Master geographic replication 99.999% High Availability with no single point of failure and on-line […]

Magento is an Open-Source e-commerce platform written in PHP using multiple other PHP frameworks such as Laminas and Symphony. Magento source code is distributed under Open Software License v3.0.

Deploying Magento is not always easy as it often requires registration. However the source code is also availble on GitHub.

Magento supports MySQL 8.0 since version 2.4.0 (July 28th 2020).

In Magento’s documentation, there is a warning about GTID support:

This is not anymore a …

Well, we are almost there.

Percona Live 2021 is just around the corner and this year comes with a very “dense” agenda.  

From my side I am giving a speech that is a high-level comparison between PXC and PS with group replication as highly available solutions.

It is a bit new for me to be at such high level, given I prefer to dig into technical, but I also think it was worth to stop and have the chance better understand what gives us what.

Anyhow this blog is not about that.

Given, as said, this year we will have a very “dense” schedule, I initially look at it and get scared.

“Too much stuff!”, that was my initial thought. Then I take a breath, reserve a couple of hours of my personal time, and start to dig-in.

In general, I have to say that thanks to the fact we are having an online event with registered speech it would be easier to attend multiple tracks also …

Introduction

In my previous two blogs on this topic I first introduced the concept of automatic thread configuration and the thread model we use in RonDB. After receiving some questions on the topic I dived a bit deeper into explaining the RonDB thread model and its thread pipeline and compared it to another similar concept called batch pipelines.

Since then I read up a bit more on the research in this area with a focus on implementations in other key-value stores. Some researchers argue that a model where one handles the request immediately is superior to a model using a thread pipeline.

RonDB Software …

Now that we’ve migrated to MySQL for our core database course, I’m building MySQL Workbench analysis problems. We start with a lecture trying to flush out a simple address, and then ask them to figure out how to link it to a customer table.

Designing it, I emphasized how it resolves the issue of a city occurring in multiple counties and states, like Fremont. Fremont occurs 17 times in the US and once in Haiti:

Naturally, I left two other design issues in the problem. I’m working through it for the first time with classes tomorrow. I hope it works well. Any comments?