The latest from the MySQL community

A while ago, we discussed the cross-site replication feature of the Percona PXC operator. Recently, a similar cross-site replication feature was introduced in the Percona (PS MySQL) operator v1.2.0, a topology based on Group Replication/InnoDB Cluster.

In this blog post, we will explore how to add a DR Cluster to an existing DC Cluster to form a ClusterSet environment, which provides a seamless switchover between DC/DR members. The good part is that all the complexity and configuration will be managed by the Percona operator, with very few setup steps required.

Group Replication …

A few thousand gcache.page.* files in a Percona XtraDB Cluster (PXC) data directory is not something you see every day. We came across a case where these files had been accumulating over time and slowly consuming disk space. So, let’s dig into what happened.

At first glance, it looked like GCache had simply stopped cleaning itself up. The investigation started by answering two simple questions: when did the files start appearing, and what changed in the cluster at that time?

Finding the starting point

The oldest files showed the issue started on July 9.

[hostx] percona@hostx: ~ $ ls -lh /var/lib/mysql/mysql-data/gcache.page.*
-rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000000
-rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000001
-rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000002
... …

“Would making this capability available help a meaningful part of the MySQL community build better applications or run better systems?”

Q1. MySQL has recently made available several features from the enterprise tier to the MySQL Community Edition. What is driving this direction?

The simple answer is that Community Edition needs to stay strong for the people who build, run, and depend on MySQL every day. That includes developers, DBAs, startups, large enterprises, and software vendors.

When we bring broadly useful capabilities into Community Edition, particularly in areas like observability, high availability, performance, and developer experience, the whole MySQL ecosystem benefits. Users get a better platform, and we get better feedback from real workloads at scale.

Recent examples include replication observability and Group Replication capabilities, …

Percona gives us room to work on our own AI-assisted projects, and I used mine to fix a problem I kept running into. Every time I wanted to try a new database feature, debug something tricky, or reproduce a customer issue, I ended up rebuilding much of the same infrastructure: DNS, TLS, Docker networking, database topologies, users and test data. Over the years, I wrote scripts to automate this but I still found myself copying and pasting post-installation steps from one lab to the next.

That repetition is what turned into DBCanvas, a self-hosted lab for designing, deploying, operating, and stress-testing multi-node database stacks on my own machine. Just design a topology on a canvas, click Deploy, and get real running nodes connected to the services and supporting infrastructure your test requires. Then, use the tools built into it or third party tools to load those …

I ran SELECT UNIQUE age FROM users on a table with a duplicated age. It returned 22, 17 and 15, the same rows SELECT DISTINCT returns. On MySQL 8 that statement stops before the table is read, because UNIQUE never entered the server’s select grammar, and DISTINCT is the modifier both servers accept. Which unique […]

MySQL 9.x added the VECTOR data type so you can store an embedding. You get a VECTOR column, functions to convert to and from text, and VECTOR_DIM() to ask how wide a vector is.

What you don't get is a way to compare two vectors. The 9.x community server has no distance function and no vector index. MySQL 8.4 has none of this at all. You can't add the missing index yourself either because vanilla MySQL's list of index types is fixed to B-tree, R-tree, hash, and full-text.

That's where VillageSQL comes in. VillageSQL is the innovation platform for MySQL that adds an extension framework (similar to PostgreSQL's extension framework) to enable permissionless innovation. Instead of waiting for a feature to be implemented in a few years in a future version of MySQL, new functionality can be dynamically added to a version of MySQL you run today.

VillageSQL already supports custom functions …

I pointed a Node script at a MySQL table and the connection succeeded. The INSERT failed on a name containing an apostrophe. Pasting values into the SQL string holds until real data arrives, then a name like O’Brien ends the run with a syntax error. Placeholders are the fix, and the driver escapes every value […]

RowDataPacket is the name MySQL hands back to Node.js, and it is the line most readers get stuck on. This is the select step end to end, from a running MySQL server to a callback whose rows you can read. What you need to run MySQL SELECT queries in NodeJS Three things, in dependency order. […]

Focusing on Percona Server 8.4.11-11

My previous post (Performance Progression of Percona Server for MySQL 8.4) did a brief review of the performance changes in Percona Server for MySQL 8.4 released in 2026. I recommend reading it first to better understand the material in this post.

Version 8.4.11-11 includes patches that deliver significant improvements in performance and scalability.

One of the most impressive illustrations of the performance bump is reflected in the following graph:

Graph 1 – Percona-Server 8.4.X with 8G buffer  [ INTERACTIVE GRAPH ][ …

MySQL ERROR 1731 'Non matching attribute INSTANT COLUMN(s)' breaks EXCHANGE PARTITION after ALGORITHM=INSTANT. This blog offers reasoning and fixtures.

The post MySQL INSTANT DDL breaks EXCHANGE PARTITION first appeared on Change Is Inevitable.