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Klaus Aschenbrenner

@sqlpassion.at
687 followers 146 following 17K posts

Senior Database Administrator in the Online-Gambling industry. SQL Server & PostgreSQL specialist during the day. Astrophotographer during the night. Triathlete in between. Loves low-level system programming in Rust.

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Reposted by Klaus Aschenbrenner
Franck Pachot @franckpachot.bsky.social · 10/09/2026
PostgreSQL MVCC is often criticized for storing old versions in place. But the question is: does it have to traverse a chain of versions to find the correct row? A new blog post to answer that: dev.to/franckpachot...
dev.to
PostgreSQL MVCC: Why Bloat Doesn't Automatically Mean Expensive Reads
One of the most persistent misconceptions about PostgreSQL MVCC is that old row versions accumulate...
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Klaus Aschenbrenner @sqlpassion.at · 30/08/2026
I've burned down a huge amount of my weekly available tokens across multiple LLMs, but I have now for my own x64 OS a working Rust-based Intel NIC driver - for the Intel 82577LM (8086:10ea) and Intel I219-V (8086:15b8) #osdev #rust #rustlang
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Klaus Aschenbrenner @sqlpassion.at · 30/08/2026
Why do Java developer wear glasses? Because they don't C# ;-)
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Klaus Aschenbrenner @sqlpassion.at · 29/08/2026
x64 ;-)
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Klaus Aschenbrenner @sqlpassion.at · 29/08/2026
My x84 OS implements now a fully working RTL8139 network driver. It can ping IP addresses on the internet, and also answers ping requests. #osdev #rust #rustlang
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Reposted by Klaus Aschenbrenner
Hannes Mühleisen @hannes.muehleisen.org · 26/08/2026
Some big news: @ducklabs.com is joining AWS, with the move expected to complete by early September. Our team will stay together in Amsterdam, with more resources to take DuckDB, DuckLake and Quack further - while the open-source Duck Stack remains free under MIT license ducklabs.com/news/2026/08...
ducklabs.com
DuckLabs to Join AWS, Projects to Remain Open Source
DuckLabs provides services around the DuckDB in-process OLAP data management system directly from its main developers.
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Reposted by Klaus Aschenbrenner
Armin Ronacher @mitsuhiko.at · 22/08/2026
Some weekend thoughts on how LLMs change the way we start new projects. lucumr.pocoo.org/2026/8/22/fa...
lucumr.pocoo.org
Fast and Hard Code
People pick languages differently with LLMs.
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Klaus Aschenbrenner @sqlpassion.at · 12/08/2026
I'm just trying to get the BYO PostgreSQL version up and running. I've created on my pg cluster a new database called "performance", and configured its connection in the json file. But when I run the service, I get the following error: "Role "darling" doesn't exist". What am I doing here wrong?
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Klaus Aschenbrenner @sqlpassion.at · 10/08/2026
The simulator can execute now LOIs (Lunar Orbit Insertions), and also Free-Return Trajectories - that saved the life of Apollo 13. Every single dot that you see, is actually *calculated* by an orbital mechanics physics engine.
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Klaus Aschenbrenner @sqlpassion.at · 10/08/2026
Having some fun with orbital mechanics, and TLIs (trans lunar injections)... 😁
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
This the customized build by EDB: www.postgresql.org/download/win...
postgresql.org
PostgreSQL: Windows installers
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
Will give it a try.
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
As far as I understand you need a special build/distribution for Postgres on Windows, because of the changed process model? Am I right on this?
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
But PostgreSQL + Windows = …. 🙈
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
I *really* like the centralized PostgreSQL data store 💪. But this also means that you need somewhere a Linux installation for it. Because - at least I think - you won’t run PosrgreSQL on Windows? 🤣
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Klaus Aschenbrenner @sqlpassion.at · 07/08/2026
Why you have deprecated the Dashboard version? And does the “Darling - headless” solution also comes with a dashboard for data analysis?
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Klaus Aschenbrenner @sqlpassion.at · 05/08/2026
Fighted against a SPID of -3. Won with 1:0 :-)
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Klaus Aschenbrenner @sqlpassion.at · 03/08/2026
Next up: feeding the data into a #PostgreSQL database with the TimescaleDB extension and analyzing it with #DuckDB. Sounds like a fun project.
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Klaus Aschenbrenner @sqlpassion.at · 03/08/2026
Over the last 6-8 hours (spread across 3 days), I’ve vibe-coded a Home Assistant dashboard that displays data from our photovoltaic system, collected via Modbus over the local TCP/IP network. Home Assistent runs on my old Odriod-H2 Mini-PC from the year 2018...
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Klaus Aschenbrenner @sqlpassion.at · 25/07/2026
Working with multiple sub-agents across multiple GitHub issues in parallel - works like a charm :-)
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Reposted by Klaus Aschenbrenner
antirez @antirez.bsky.social · 25/07/2026
I tried to adapt the transcript of my video "Being Linus Torvalds" into an english language blog post here: antirez.com/news/171
antirez.com
Being Linux Torvalds - <antirez>
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Reposted by Klaus Aschenbrenner
Exoscale - The European Public Cloud @exoscale.com · 24/07/2026
What actually happens inside an LLM after you press enter? Our blog post maps out the mechanical journey of a prompt through the forward pass. 👉 www.exoscale.com/blog/llm-fro... . . . #AI #LLM #inference
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Klaus Aschenbrenner @sqlpassion.at · 17/07/2026
Ok, that was quite fast... 😱
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Klaus Aschenbrenner @sqlpassion.at · 17/07/2026
Hello Kimi K3 :-) #ai #llm #agenticcoding
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Reposted by Klaus Aschenbrenner
Chrissy LeMaire @funbucket.dev · 16/07/2026
Linus Torvalds, my man! *finger gun emoji*
per linus torvalds: I realize that some people really dislike AI, but this is an area where I'm willing to absolutely put my foot down as the top-level maintainer.

Linux is not one of those anti-AI projects, and if somebody has issues with that, they can do the open-source thing and fork it.

Or just walk away.

AI is a tool, just like other tools we use. And it's clearly a useful one.

It may not have been that "clearly" even just a year ago, but it's no longer in question today.

There are other questions around AI (like what the economy of it will actually look like in the end), but "is it useful" is no longer one of those questions. Anybody who doubts that clearly hasn't actually used it.

Yes, it can also be a somewhat painful tool, both for maintainer workloads and just from a "it keeps finding embarrassing bugs" standpoint.

But the solution is not to put your head in the sand and sing "La La La, I can't hear you" at the top of your voice like some people seem to do.
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Reposted by Klaus Aschenbrenner
Franck Pachot @franckpachot.bsky.social · 01/07/2026
Can PostgreSQL perform multi-block reads to reduce system calls? Yes, it's coming in PG19 with IO combine prefetching. What about TOASTed documents? Here's a new blog post: dev.to/franckpachot...
dev.to
Multi-block buffered reads in PostgreSQL 19 (IO combine & prefetch)
PostgreSQL scans operate at the page level: the buffer manager fetches one 8 KB page (BLCKSZ) at a...
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Klaus Aschenbrenner @sqlpassion.at · 28/06/2026
I have now a full-blown working UEFI boot path in my OS - incl. a simple AHCI driver to access the SATA based SSD drive with its FAT32 ESP partition. 100% pure Rust code (not a single asm file!), without any dependencies to other crates! #rust #rustlang #x64 #computerscience
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Klaus Aschenbrenner @sqlpassion.at · 28/06/2026
How to escape the heat wave? Starting a 100K “red eye” bike ride at 05:00am in the morning… 😴😴😴
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Klaus Aschenbrenner @sqlpassion.at · 26/06/2026
Running my own OS in Proxmox - booted via UEFI :-)
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Klaus Aschenbrenner @sqlpassion.at · 23/06/2026
I can boot now my x64 kernel on native UEFI hardware - like my AMD Ryzen system with 128 GB RAM. It uses the provided GOP framebuffer to draw a pseudo console to the screen. The legacy BIOS boot path (on older hardware) supports now also the VBE-based graphics mode for the console. #osdev #rust
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Klaus Aschenbrenner @sqlpassion.at · 23/06/2026
My prediction: when you don't incorporate AI into your daily workflow, you will not be needed anymore in the software industry within the next 12 - 24 month.
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Klaus Aschenbrenner @sqlpassion.at · 22/06/2026
+1000!
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Klaus Aschenbrenner @sqlpassion.at · 19/06/2026
Very well, and much safer than C. And the resulting code has also a much bettwrr quality, because you can solve problems with nicer language constructs.
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Klaus Aschenbrenner @sqlpassion.at · 18/06/2026
It's the 1st time in my life that I've implemented my own UEFI loader - entirely in Rust - without any external dependencies. #Rust #rustlang #computerscience
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Klaus Aschenbrenner @sqlpassion.at · 17/06/2026
Check it out at github.com/SQLpassion/o...
github.com
GitHub - SQLpassion/osdev: This repository contains OS development specific code and tutorials
This repository contains OS development specific code and tutorials - SQLpassion/osdev
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Klaus Aschenbrenner @sqlpassion.at · 17/06/2026
I have migrated now my whole x64-based OS entirely to Rust. There is NO single line of C code anymore - just a few pure assembly files! In addition, I'm also providing a VScode based Dev-Container, with which you can even build and run the OS in your browser! #rust #rustlang #osdev #computerscience
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Klaus Aschenbrenner @sqlpassion.at · 14/06/2026
Finished the first bicycle race of my life: the „Dolomitenradrundfahrt“ in East-Tyrol. 110km with 1700m ascent! 🥵 4:19h, and the 96th place (out of 153 participants) within my age group! 💪
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Klaus Aschenbrenner @sqlpassion.at · 09/06/2026
What could go wrong, if you have to safeguard a new LLM (Claude Fable 5) for cybersecurity, biology and chemistry related prompts... www.anthropic.com/news/claude-...
anthropic.com
Claude Fable 5 and Claude Mythos 5
Today we’re launching Claude Fable 5: a Mythos-class model that we’ve made safe for general use.
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Klaus Aschenbrenner @sqlpassion.at · 31/05/2026
What a day: finished my 1st Aqua Bike competition. 53th out-of-water (the last one!), and finished after the bike split at the 26th place - in 3:48h! 💪
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Klaus Aschenbrenner @sqlpassion.at · 29/05/2026
Which motherboard do you use?
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Klaus Aschenbrenner @sqlpassion.at · 29/05/2026
For you? 🫠
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Klaus Aschenbrenner @sqlpassion.at · 09/04/2026
What a day! mMy longest bike ride of my life! 😎 #mallorca
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Reposted by Klaus Aschenbrenner
Mathias Lafeldt @mathias.blog · 14/03/2026
This is one of the most balanced critiques of AI I've read so far. "Reviewing AI output all day without the dopamine of creation is not a sustainable job description." tomwojcik.com/posts/2026-0...
tomwojcik.com
What AI coding costs you | Tom Wojcik
What's the effect of the prolonged AI usage among coders and is it tracked correctly, if it all?
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Reposted by Klaus Aschenbrenner
Florian Aigner @florianaigner.at · 11/03/2026
Max Schrems ist ein Jurist, der mit seinem Einsatz für Datenschutz- und Grundrechte international höchst erfolgreich war. Peter Steinberger reitet eine Bubble, die uns derzeit alle mit einem ganzen Bündel gefährlicher Probleme konfrontiert. Österreichische Medienpolitik so:
Screenshot aus der Presse:
Pröll: "Österreich braucht mehr Steinberger und weniger Schrems"
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Reposted by Klaus Aschenbrenner
DuckDB @duckdb.org · 09/03/2026
We released DuckDB v1.5! This release comes with a “friendly CLI” client, a new (opt-in) PEG parser, support for VARIANT types and many lakehouse features. It also ships a new network stack, a reworked geospatial extension, Azure writes and an ODBC scanner. Read more at duckdb.org/2026/03/09/a...
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Reposted by Klaus Aschenbrenner
Alex Miller @alexmillerdb.bsky.social · 09/03/2026
[VLDB '25] MD-MVCC: Multi-version Concurrency Control for Schema Changes in Azure SQL Database www.vldb.org/pvldb/v... A great discussion of the end-to-end impact of allowing multiple versions of schema metadata information to be live concurrently, in a real, production system.
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Reposted by Klaus Aschenbrenner
antirez @antirez.bsky.social · 08/03/2026
New blog post: "GNU and the AI reimplementations" antirez.com/news/162
antirez.com
GNU and the AI reimplementations - <antirez>
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Klaus Aschenbrenner @sqlpassion.at · 06/03/2026
CU2, and there still all the various performance problems regarding JSON indexes… 🧐
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Klaus Aschenbrenner @sqlpassion.at · 06/03/2026
It's so "funny" when #ChatGPT hallucinates about SQL Server 2025 feature internals, which are not documented anywhere. And then it says "sorry", because it delivered garbage to you... #StrangeNewWorld
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Klaus Aschenbrenner @sqlpassion.at · 05/03/2026
I wish you all the best, a fast recovery, and stay strong! 💪
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