Press "Enter" to skip to content

Author: Kevin Feasel

Thoughts on Multi-Primary Replication in PostgreSQL

Published 2025-06-19 by Kevin Feasel

Jan Wieremjewicz wants to know if you really need it:

Active-active, also referred to as multi-primary, is a setup where multiple database nodes can accept writes at the same time and propagate those changes to the others. In comparison, regular streaming replication in PostgreSQL allows only one node (the primary) to accept writes. All other nodes (replicas) are read-only and follow changes.

In an active-active setup:

  • There is no single point of write.
  • Applications can write to any node.
  • The database needs a way to sort out conflicts when two nodes try to concurrently change the same data.

Read on for some of the challenges around this, tooling that is available, and thoughts on when this can be important.

Comments closed

Restoring a Database via dbatools

Published 2025-06-18 by Kevin Feasel

David Seis digs into the Restore-DbaDatabase cmdlet:

In this blog post, we will audit the dbatools command Restore-DbaDatabase. I will test, review, and evaluate the script based on a series of identical steps. Our goal is to provide insights, warnings, and recommendations to help you use this script effectively and safely. Restore-DbaDatabase is powerful tool to automate the restore of any database, and it works well in automated solutions such as daily refreshes or weekly refreshes of production to a lower environment.

David’s blog post takes a look at the cmdlet’s functionality, but also thinking about it from a security perspective.

Comments closed

EchoLeak: Zero-Click Copilot Vulnerability

Published 2025-06-18 by Kevin Feasel

Alex Woodie reports on a vulnerability:

The Microsoft Copilot vulnerability, dubbed EchoLeak, was listed as CVE-2025-32711 in the NIST’s National Vulnerability Database, which gave the flaw a severity score of 9.3. According to Aim Labs, which discovered EchoLeak and shared its research with the world last week, the “zero-click” flaw could “allow attackers to automatically exfiltrate sensitive and proprietary information from M365 Copilot context, without the user’s awareness, or relying on any specific victim behavior.” Microsoft patched the flaw the following day.

The blog post linked above is pretty interesting. Microsoft has patched the vulnerability, so this particular attack vector shouldn’t be an issue. But it will certainly open up the doors for more fun ways of exploiting generative AI-based services.

Comments closed

Maintaining Statistics Information Post-Update in PostgreSQL 18

Published 2025-06-18 by Kevin Feasel

Laurenz Albe takes a peek at an upcoming feature:

Everybody wants good performance. When it comes to the execution of SQL statements, accurate optimizer statistics are key. With the upcoming v18 release, PostgreSQL will preserve the optimizer statistics during an upgrade with dump/restore or pg_upgrade (see commit 1fd1bd8710 and following). With the beta testing season for PostgreSQL v18 opened, it is time to get acquainted with the new feature.

It’s kind of wild to me that this wasn’t in place years ago for PostgreSQL.

Comments closed

First Thoughts on Rancher Desktop

Published 2025-06-17 by Kevin Feasel

Steve Jones tries something new:

I’ve been very happy with Docker Desktop for years, running it on both laptop and desktop. However, a corporate decision was made to move to Rancher Desktop, so I now have an unexpected “opportunity” to learn something new.

Here’s a short post on how things went on the desktop and laptop.

I’m guessing corporate made the switch because of Docker for Desktop’s licensing costs. It is kind of funny how, in the Windows and even MacOS world, “Docker” is synonymous with “container,” whereas in the Linux world, that’s not at all the case.

Comments closed

Multithreading and Multiprocessing in Python

Published 2025-06-17 by Kevin Feasel

Jessica Wachtel explains how two systems work in Python:

Let’s use a simple example to understand them: a mechanics shop. Concurrency happens when one mechanic works on several cars by switching between them. For example, the mechanic changes the oil in one car while waiting for a part for another. They don’t finish one car before starting the next, but they can’t do two tasks at exactly the same time. The tasks overlap in time but don’t happen simultaneously.

Click through for the analogy, how it applies to Python, and tips and tricks around each.

Comments closed

The Downsides of SELECT FOR UPDATE in PostgreSQL

Published 2025-06-17 by Kevin Feasel

Laurenz Albe explains why SELECT FOR UPDATE is rarely the right call:

Recently, while investigating a deadlock for a customer, I was again reminded how harmful SELECT FOR UPDATE can be for database concurrency. This is nothing new, but I find that many people don’t know about the PostgreSQL row lock modes. So here I’ll write up a detailed explanation to let you know when to avoid SELECT FOR UPDATE.

Click through for the full explanation.

Comments closed