The latest from the MySQL community

Welcome back. This issue covers five weeks rather than the usual one — the gap since the August issue took in Percona Live Amsterdam, the launch of the OurSQL Foundation, and the run-up to the MySQL Galera Cluster end of life on 30 September.

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MySQL News

Note: Aggregated MySQL news can be found at Planet for MySQL Community and Planet MySQL (Oracle curated)

DISTANCE() and VECTOR_DISTANCE(): Vector Similarity in Percona Server for MySQL …

TL;DR

Percona Server for MySQL 9.7.2-2 now supports DISTANCE() for vector similarity scoring directly in SQL (COSINE, EUCLIDEAN, MANHATTAN, DOT metrics). This is the compute primitive you need to rank or filter embeddings by similarity directly in SQL. ANN indexing (e.g. HNSW, IVF) is the next milestone for fast large-scale similarity search; and this function provides the scoring layer that indexing strategies will further accelerate.

Why we’re adding this

MySQL’s native DISTANCE() and VECTOR_DISTANCE() functions are only available in HeatWave MySQL on OCI, not included in Community or Commercial MySQL, and limited to three metrics (COSINE, DOT, EUCLIDEAN). Percona is bringing the same capability to anyone running Percona Server for MySQL on any supported platform.

MySQL 9.7 already supports the VECTOR data type (TO_VECTOR() and FROM_VECTOR() functions) for storing embeddings. DISTANCE() …

For this quick verification of the 0.0.7 development branch of VillageSQL with the new vsql-vector plugin. Recreate the VillageSQL Percona Live presentation using MySQL version 8.4 and SVECTOR. Demonstrate a more detailed example using SVECTOR(1024) string embedded data.

This September and October, Heather VanCura will meet with MySQL users, contributors, developers, DBAs, customers, and community leaders across Brazil and Europe. With more than 30 years of innovation behind it, the MySQL community is entering an important new phase. The focus is on expanding engagement, collaboration, and contributions while increasing and driving innovation and unification of the ecosystem. The tour will […]

We are pleased to announce a new extension for VillageSQL Server that enables running DuckDB queries from within MySQL and joining those results with MySQL query results. DuckDB has emerged as the analytical engine of choice for fast querying of data formats such as Parquet. It excels with analytics queries because of its columnar storage, vectorized execution, and embedded architecture. Applications often need to combine the results of analytical queries with operational results, though. There are multiple ways to do this, but many are suboptimal when the query's results need to be returned to an application that is connected to an operational database such as MySQL.

The new vsql-duckdb extension from VillageSQL solves this by embedding DuckDB inside MySQL, keeping your existing database …

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 […]