HNHacker News
TopNewBestAskShowJobs

jankotek

570 karma · joined December 22, 2016

Java/Scala hacker. Astronomy nerd.

www.mapdb.org

www.kotek.net

submissionscomments
jankotek··on Are 14 people really looking at that product? (2020)
Perhaps it is just travel anxiety? I book hotels a few hours in advance and stats like "only 2 rooms left", are usually correct when I check with hotel reception. At least in Europe booking.com is much better than competition. It has loyalty discounts, transparent pricing and consistent experience. Reviews and descriptions are actually useful, not BS. Emails I get are usually "place you looked at become 30% cheaper".
jankotek··on Elfshaker: Version control system fine-tuned for binaries
Does it make a sense to turn it into fuse fs, with transparent deduplication?
jankotek··on Office 2000 is good to go
Win95 had very strict and consistent UI style. Office2k and Win2k were peak of this consistency. After that came WinXP and mismatch of inconsistent UI styles.
jankotek··on Java Virtual Threads Preview
Java uses some memory for stack, about 1MB for each thread.
jankotek··on CEOs are at their wits’ end – they don’t know how to get their employees back in
For start they could provide private offices. Open-plan office is hygienically unsuitable for regular use.
jankotek··on Samsung kills the cameras on the Galaxy Z Fold 3 if you unlock the bootloader
I had run LineageOS for some time. It works, but FDroid is missing too many apps, even opensource like Signal. I have to update apks manually every few months.
jankotek··on Japan is holding back as the world rushes toward electric cars
Japan has very good public transport, and does not really need cars.

In america the question is why invest in carbon based transportation? It is "obsolete technology"! In japan cars are "obsolete"!

jankotek··on A shot to prevent Lyme disease could be on its way
Better to eradicate ticks.
jankotek··on Tesla Owner Billed over $14,000 for Accidental Full Self-Driving Purchase
$10 nozzle repair requires new battery pack for $16,000. Call it what you want, but that is not green car.
jankotek··on Why does man print “gimme gimme gimme” at 00:30? (2017)
Why should people care about some 50 year old obscure cultural references? It is not 1980ies, when 99% unix users were from western culture.
jankotek··on Facebook and Google Are Not Public Utilities
Many public institutions treat Google as public utility. Children can not attend school, unless they agree to privacy policy on school issued Chromebook. Town hall meetings announcements are only on FB...

If those are not public utilities, there should be law to prevent public institutions from using them.

I always seen it as public threat that politicians are on private social media, what if private company declares war on our behalf?

jankotek··on Licenses alone do not govern behavior in open source
OS author also distributes, maintains and supports project. Just compiling some opensource projects (Firefox, Chromium) is very complicated.

I am not sure what happened here. But if large project would use outdated or broken version, author may get bombarded with support requests for problem, that was solved years ago.

jankotek··on Show HN: DeepHN – Full-text search of 30M Hacker News posts and linked webpages
It searches content of referenced webpages. Also has filtering by year intervals (for example 2012-2016), domains, tags etc.. And I find usability better.

I think it is great product.

jankotek··on Why was cycling not included in the ancient Olympics? (2004) [pdf]
Chariots were invented, but lightweight chariots were VERY hightech and expensive, something like Ferrari today. See youtube link.

https://www.youtube.com/watch?v=0Loti-WBK_k

jankotek··on Ask HN: Who wants to be hired? (April 2021)
Location: Prague, Czechia

Remote: yes, Europe

Willing to relocate: no, remote only, preferably async

Technologies: java, jvm, data, kotlin, scala, defi

CV: https://github.com/jankotek , CV on request

Email: jan @ kotek d0t net

I am consultant with 15 years java experience, last 10 years I worked on opensource projects. I worked on IDE, compilers, but mostly on database engines and data processing. All Java. I have some experience in cryptography and defi. My clients were Apple, a few banks, and some startups that are now worth multi billions. More details on request.

Looking for part time, JVM related, temp contracts. Code audit, refactoring, performance fix...

jankotek··on BPF for storage: an exokernel-inspired approach
Many databases can bypass filesystem and use block device (partitions) directly. But modifying NVMe drivers is pretty novel approach. Maybe Redis compiled into Linux kernel is not bad idea :)
jankotek··on ZGC – What's new in JDK 16
It really depends on application and complexity of object graph. Short lived object usually have low overhead. Long lived objects with huge heap may cause a problem.

In past GC had bad reputation for increased and unpredictable latencies. In old JVMs GC would pause execution to traverse object graph.

In general do not worry about GC, unless you run into performance issues. If performance is a problem, run continuous profiler such as Flight Recorded. It has very little overhead.

jankotek··on Ask HN: Oldest piece of hardware a user could access the internet with?
Human brain. IP protocol is computable by humans. There is even RFC for transferring packets over pigeons.
jankotek··on Faster A fast concurrent persistent key-value store and log, in C# and C++
Saturating modern SSDs is not that hard, if datastream is constant. Write performance usually degrades rapidly after couple of hours/days, once caches are filled and fragmentation grows.

But I totally agree modern SSDs will cause shift in computer and software architecture. Dealing with async disk IO is very frustrating.

jankotek··on A Look at the CPU Security Mitigation Costs Three Years After Spectre/Meltdown
> [a]: Obviously, for absolute security, a hammer and/or a shredder does much better.

This still leaves large pieces of magnetic plates intact. At uni we could read some data from floppies that went through shredder.

Hammer and shredder is NOT "absolute security".

jankotek··on GitHub blocks entire company because one employee was in Iran
Hell no!

In this case Github is just unreliable piece of infrastructure. My phone provider bans me for receiving phone call from wrong country? Nice joke.

jankotek··on Show HN: Organizedly – Linked notes, todo's, calendar and queries
Hm, yet another cloud based app with zero privacy and questionable life expectancy. Personal notes are very valuable and may go back 30 years.

What I need:

- self hosted server app

- data stored in human readable independent format with revision history (text+git)

- auditable security

- clients for web, mac, android

- integration with other platforms

jankotek··on The naval shipworm helped bring about the Industrial Revolution
Ships were often carried across land, for example over Isthmus of Corinth. Ship wood was also expensive, maybe they took and reused some parts...
jankotek··on The naval shipworm helped bring about the Industrial Revolution
It quotes Herodotus, this is first link from google, wiki has some pages as well. I am not an historian, but it seems credible. Some details are matching.

https://en.m.wikipedia.org/wiki/Necho_II

jankotek··on The naval shipworm helped bring about the Industrial Revolution
Phoenicians circumnavigated Africa, Greeks knew about that.

https://www.labrujulaverde.com/en/2018/11/the-egyptian-phoen...

jankotek··on Flow Browser Preview on the Raspberry Pi 400
Main selling point of Presto Opera engine was it could run on any CPU. Often on poor feature phones, without MMU, floating point arithmetic...

Raise of cheap full featured ARM CPUs made it obsolete.

jankotek··on Bees Are Now Considered the Most Important Living Thing on Earth
》Bees are the only living thing on earth that doesn’t carry any type of pathogen, including bacteria, viruses, and fungi.

That is simply not true. Bees have many parasites, fungi, diseases ...

jankotek··on What’s the best non-smart TV sold today?
Hacking used to be about modifying your hardware.

Smart TVs are relatively cheap compared to large industrial displays. They are also reliable. If you need large secure (no wifi) display, this is pefectly valid option.

jankotek··on What’s the best non-smart TV sold today?
Perfectly valid solution, and it gets downvoted on Hacker News...
jankotek··on A family with no fingerprints
Washing dishes and some types of work may also erase fingerprints. Friend had troubles to enter US as a tourist.
Page 1 of 18Next →