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 …

“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, …

Starting with Percona XtraDB Cluster (PXC) 8.0, replication traffic encryption is enabled by default. That said, it’s common to find clusters running without TLS that suddenly need it: a new compliance requirement, an audit finding, a network segment that is no longer considered trusted.

PXC has a variable for exactly that case, pxc-encrypt-cluster-traffic, which handles SSL encryption for inter-node traffic, including State Snapshot Transfer (SST), Incremental State Transfer (IST), and the group communication the nodes use for replication.

The variable is not dynamic, and turning it on normally costs a full cluster restart since the node that encrypts traffic listens on ssl:// while its peers are still on tcp://. If a node joins the cluster with TLS enabled while remaining nodes don’t, the restarting node fails to reach out to the other peers with the following error:

2026-09-02T02:16:02.359992Z 0 [Note] [MY-000000] …

There are a few cryptography tasks that are common to many backends. For example, you should store passwords such that a database leak doesn't expose them, you should sign payloads so the receiving side can verify them, you should keep a column's data unreadable outside the database, and you should mint tokens an attacker cannot guess. MySQL's built-in functions cover part of that ground but fall short for many users. The SHA2() function will hash a password, but nothing salts it for you, so two people who pick the same password end up with the same stored value. MySQL does not have a built-in HMAC function. An HMAC is the keyed hash a receiver uses to tell a real message from a forged one.

When a database doesn't solve a problem natively, the work invariably moves up into application code, where every service reimplements it just a little bit differently. This adds ongoing maintenance complexity.

The …

When setting up a new database for an application, high availability (HA) is one of the main priorities. Let’s assume for this example that you chose to use a Percona XtraDB (PXC) cluster to host your database. But how does the application know which PXC node is healthy and can receive application traffic? Introducing a cluster of ProxySQLs can solve this problem, as ProxySQL will healthcheck the database nodes and route the application traffic to the healthy nodes. However, now the HA problem comes up again: how does the application know which ProxySQL host is healthy?

Putting “one more component” in front of your servers to make them highly available just shifts the problem up by one layer. From making the database HA, to making ProxySQL HA, to needing to make HAProxy HA and so on…

At some point, you may land on the common HA strategy, keepalived, but BGP ECMP is a powerful alternative worth considering.

What …

MySQL keeps restarting on its own. The alert fires at 06:37, the database is back before anyone opens a laptop, the log holds a wall of Lost connection to MySQL server during query, and uptime says 41 days. The next morning it is 06:12, the morning after that nothing.

On a default Ubuntu or Debian server, unattended-upgrades installs security updates on a daily systemd timer, and when one touches MySQL, dpkg stops mysqld, upgrades the data directory, and starts it again. Nothing rebooted. The database was replaced underneath a host that never stopped running. We measured it on an Amazon Elastic Compute Cloud (EC2) instance.

Is this a MySQL problem?

No. It comes from the Debian package’s install script, generated by the standard packaging tooling and marked as such in the file. Every Debian package carrying a daemon ships the same block: the packaging can’t tell a …

In this guide, we explain 150+ SQL commands in simple words, covering everything from basic queries to advanced functions for 2026. We cover almost every SQL command that exists in one single place, so you never have to go search for anything anywhere else. If you master these 150 commands, you will become an SQL […]

Oracle plans to move MySQL security updates toward a monthly cadence, supplementing the current quarterly Critical Patch Update (CPU) schedule. These monthly Critical Security Patch Update (CSPU) releases will be issued only when needed to address critical security or stability issues; they are not a fixed monthly release commitment. These CSPU releases will focus on […]

Two recent posts on the Percona blog caught my attention. In Replicating from InnoDB into a DuckDB storage engine and The DuckDB MySQL engine at 500 GB, Evgeniy Patlan wired DuckDB into mysqld as a storage engine, pointed row-based replication at it, and measured it at TPC-H scale factor 500. The numbers are striking: loads 25 times faster than InnoDB, one fifth of the disk, and the full 22-query TPC-H suite done in 186 seconds where InnoDB needed about 28 hours and never finished four of the queries.

The posts are also honest about the cost. The work is experimental. The worst bug found was silent data loss on every replicated transaction: the two-phase commit code for mixed-engine transactions dropped prepared DuckDB transactions …

The MySQL Community team will continue to be active across conferences, user group meetups, open source events, and regional community activities throughout August, September, and October 2026.  While some of our August events were featured in our previous event update, we’ve included them here again with the latest information. Whether you’re interested in learning about MySQL 9.7 LTS, exploring the latest features in […]