Jaromir Hamala

I started a software research company

notes.eatonphil.com/2026-02-25-i...

How a 40-Line Fix Eliminated a 400x Performance Gap | QuestDB A deep dive into an OpenJDK commit that replaced slow /proc file parsing with a single syscall, revealing obscure Linux kernel internals and a 20-year-old optimization opportunity.

I did some OpenJDK commit exploration and I thought I could blog about it too. Here it is: questdb.com/blog/jvm-cur...

#Java "Magic" types: The ones you can't name (non-denotable types)

https://www.linkedin.com...

GitHub - ibraheemdev/modern-unix: A collection of modern/faster/saner alternatives to common unix commands. A collection of modern/faster/saner alternatives to common unix commands. - ibraheemdev/modern-unix

github.com/ibraheemdev/...

A collection of "modern" #Unix tools

How a Kernel Bug Froze My Machine: Debugging an Async-profiler Deadlock | QuestDB How I investigated and worked around a kernel bug that caused async-profiler to freeze my machine whenever I tried to use a profiler.

My machine froze when I connected async-profiler and I wrote an article about it.

It involves debugging a half-dead Linux kernel, performing live surgery on a frozen CPU with GDB, pulling off a questionable resurrection and other party tricks :)

Read the full autopsy: questdb.com/blog/async-p...

TIL: Early exit makes 'javac' to duplicate 'finally' blocks. Interesting read: www.benf.org/other/cfr/fi...

📝 Blogged: "On Idempotency Keys"

Discussing several options for ensuring exactly-once processing in distributed systems using idempotency keys, from UUIDs to monotonically increasing sequences.

👉 www.morling.dev/blog/on-idem...

#opensource #opentowork | Andres Almiray Hi everyone! An ongoing reorganization at my current employer has prompted me to seek for a new role and would appreciate your support. I'm open to remote (anywhere) and hybrid roles in Switzerland (...

Hi everyone! An ongoing reorganization at my current employer has prompted me to seek for a new role and would appreciate your support.

I'm open to remote (anywhere) and hybrid roles in Switzerland. I have 25+ years experience as a software developer, 8 as devrel www.linkedin.com/posts/aalmir...

The Mystery of the Phantom Quote in My CI Builds | QuestDB How a phantom single quote from bash's set -x caused random CI build failures through a race condition between stdout and stderr in Azure Pipelines.

My new bug: Race between stdout and stderr causing CI builds to fail.

questdb.com/blog/azure-p...

From Rust to Reality: The Hidden Journey of fetch_max | QuestDB A compiler deep-dive tracing Rust’s AtomicU64::fetch_max from macro expansion and rustc intrinsics through LLVM’s atomicrmw umax and AtomicExpandPass to the final x86-64 CAS loop

My new blog post:
questdb.com/blog/rust-fe...

If you like seeing how high-level code becomes low-level reality, then you will like it. Enjoy!

From the Brno community on Reddit: Projekt: Polední meníčka v Brně Explore this post and more from the Brno community

Jestli chodíte v Brně na obědy do restaurací, tak vyzkoušejte tuhle novou stránku www.lepsimenu.cz s přehledem poledních menu. www.reddit.com/r/Brno/s/qA4...

TIL: Columbia (US places) and Colombia (South American country) have different spellings, though they sound identical.

Both named after Christopher Columbus but spelt differently in English vs Spanish, I guess?

Oracle Hint of the Day: INDEX_FFS for a Fast Full index Scan.

When you're really trying to tell the optimizer how you feel about that full table scan suggestion😂

SELECT /*+ INDEX_FFS ( o order_pk ) */ COUNT(*)
FROM order_items l, orders o
WHERE l.order_id > 50
AND l.order_id = o.order_id;

I only just learned about CLWB. Is it used/useful beyond writing to non-volatile RAM? Is there a non-volatile RAM which works with Ryzen? 😮

Modern microprocessors, a 90-minute guide: www.lighterra.com/papers/moder...

a cartoon of a devil with a speech bubble that says " lol " ALT: a cartoon of a devil with a speech bubble that says " lol "

Breaking news: Archaeologists discover ancient scroll revealing Satan's proudest invention wasn't fire or sin, but 1-indexed arrays.

A source code listing showing how to use the new Kafka share group API to acknowledge messages one by one.

🚨📝 Blogged: "Let's Take a Look at... KIP-932: Queues for Kafka!"

Kicking off a new blog series to explore all sorts of interesting technologies, projects, and services in the data and streaming space. Up first: the new #ApacheKafka 4.0 API for queue semantics.

👉 www.morling.dev/blog/kip-932...

bugs.openjdk.org/browse/JDK-7...

Interesting issue in OpenJDK's UUID.compareTo(): It uses signed comparisons, which leads to unexpected sorting when the highest bit in either word is set. It can't be fixed since altering a sort order between versions is a big no-no.

I learned about Chicory thanks to this, It looks pretty cool!