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Show HN: I made a calculator that works over disjoint sets of intervals

https://victorpoughon.github.io/interval-calculator/
108•fouronnes3•6h ago•14 comments

Why is IPv6 so complicated?

https://github.com/becarpenter/misc/blob/main/why6why.md
12•signa11•49m ago•1 comments

Claude Design

https://www.anthropic.com/news/claude-design-anthropic-labs
996•meetpateltech•16h ago•656 comments

Category Theory Illustrated – Orders

https://abuseofnotation.github.io/category-theory-illustrated/04_order/
7•boris_m•41m ago•0 comments

Towards trust in Emacs

https://eshelyaron.com/posts/2026-04-15-towards-trust-in-emacs.html
86•eshelyaron•2d ago•8 comments

Measuring Claude 4.7's tokenizer costs

https://www.claudecodecamp.com/p/i-measured-claude-4-7-s-new-tokenizer-here-s-what-it-costs-you
594•aray07•15h ago•417 comments

All 12 moonwalkers had "lunar hay fever" from dust smelling like gunpowder (2018)

https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/The_toxic_side_of_the_Moon
311•cybermango•13h ago•184 comments

Spending 3 months coding by hand

https://miguelconner.substack.com/p/im-coding-by-hand
187•evakhoury•15h ago•190 comments

Rewriting Every Syscall in a Linux Binary at Load Time

https://amitlimaye1.substack.com/p/rewriting-every-syscall-in-a-linux
20•riteshnoronha16•4d ago•6 comments

A simplified model of Fil-C

https://www.corsix.org/content/simplified-model-of-fil-c
159•aw1621107•9h ago•83 comments

Are the costs of AI agents also rising exponentially? (2025)

https://www.tobyord.com/writing/hourly-costs-for-ai-agents
181•louiereederson•2d ago•42 comments

Isaac Asimov: The Last Question (1956)

https://hex.ooo/library/last_question.html
699•ColinWright•19h ago•278 comments

Brunost: The Nynorsk Programming Language

https://lindbakk.com/blog/introducing-brunost
40•atomfinger•4d ago•11 comments

Show HN: Smol machines – subsecond coldstart, portable virtual machines

https://github.com/smol-machines/smolvm
310•binsquare•14h ago•93 comments

Show HN: PanicLock – Close your MacBook lid disable TouchID –> password unlock

https://github.com/paniclock/paniclock/
180•seanieb•14h ago•74 comments

Slop Cop

https://awnist.com/slop-cop
153•ericHosick•16h ago•94 comments

Hyperscalers have already outspent most famous US megaprojects

https://twitter.com/finmoorhouse/status/2044933442236776794
180•nowflux•14h ago•142 comments

"cat readme.txt" is not safe if you use iTerm2

https://blog.calif.io/p/mad-bugs-even-cat-readmetxt-is-not
165•arkadiyt•12h ago•87 comments

NASA Force

https://nasaforce.gov/
260•LorenDB•15h ago•263 comments

Middle schooler finds coin from Troy in Berlin

https://www.thehistoryblog.com/archives/75848
223•speckx•16h ago•100 comments

Landmark ancient-genome study shows surprise acceleration of human evolution

https://www.nature.com/articles/d41586-026-01204-5
68•unsuspecting•8h ago•61 comments

Making Wax Sealed Letters at Scale

https://waxletter.com/
12•hjconstas•2d ago•10 comments

Casus Belli Engineering

https://marcosmagueta.com/blog/casus-belli-engineering/
29•b-man•6h ago•6 comments

It is incorrect to "normalize" // in HTTP URL paths

https://runxiyu.org/comp/doubleslash/
3•pabs3•1h ago•0 comments

NIST gives up enriching most CVEs

https://risky.biz/risky-bulletin-nist-gives-up-enriching-most-cves/
193•mooreds•16h ago•46 comments

The Unix executable as a Smalltalk method (2025) [video]

https://www.youtube.com/watch?v=sZjPQ7vtLNA
49•surprisetalk•1d ago•3 comments

Arc Prize Foundation (YC W26) Is Hiring a Platform Engineer for ARC-AGI-4

https://www.ycombinator.com/companies/arc-prize-foundation/jobs/AKZRZDN-platform-engineer-benchma...
1•gkamradt_•10h ago

Introducing: ShaderPad

https://rileyjshaw.com/blog/introducing-shaderpad/
80•evakhoury•2d ago•16 comments

The GNU libc atanh is correctly rounded

https://inria.hal.science/hal-05591661
85•matt_d•3d ago•17 comments

Generating a color spectrum for an image

https://amandahinton.com/blog/generating-a-color-spectrum-for-an-image
43•evakhoury•2d ago•7 comments
Open in hackernews

Pglocks.org

https://pglocks.org/
80•hnasr•11mo ago

Comments

whilenot-dev•11mo ago
I'm a bit lost here.

Locking is a challenging problem in complex systems. Is this list to be interpreted as a "TODO: get rid of locking conflicts in future releases" or more a "NOTE: be aware there are known conflicts that will not change - find ways to work around them"?

EDIT: Also, is the creation of this list an automated or a manual effort?

tux3•11mo ago
I think this is intended as educational material, not a list of things to fix.

The locks are here by necessity, it is not so easy at all to get rid of them. And even in special cases where it is possible, the complexity you have to introduce is not to be taken lightly...

If even a tenth of these disapppeared, it would be incredible, in a very surprising way.

atombender•11mo ago
The creator looks like a developer and teacher, not a Postgres core team member. So I assume this is for documentation purposes.

I actually like this a lot, as there isn't a single place in the Postgres documentation that lists all the possible locks; it's spread out all over. Having a quick reference for what kinds of commands you'd be blocking with your transaction is valuable.

It's pretty evident that the pages have been programmatically generated, but I'd love know what it's generated from. I think you can derive this information from the documentation, but not sure if you can do it in an automated way without an LLM.

braiamp•11mo ago
> there isn't a single place in the Postgres documentation that lists all the possible locks

Did you read this page? https://www.postgresql.org/docs/current/explicit-locking.htm...

atombender•11mo ago
That's a great page, but it has several issues.

First, it isn't complete; as I said, the locking behaviour is spread out all over the Postgres documentation. For example, that page doesn't list what locks DROP INDEX takes. To find that out, you have to go to the documentation page for that command and read it carefully. In fact, really carefully — the locking behaviour is only documented under the section about CONCURRENTLY.

The page also doesn't list what possible commands are then blocked. Locks interact in subtle (and incorrectly named!) ways that are explained in the tables on that page ("Conflicting lock modes"), so to understand if something will block something else you have to look at the two commands you are curious about and then look at how their locks interact.

gulcin_xata•11mo ago
I agree, it is not so straightforward to find out.
braiamp•11mo ago
These are database locks, which means that depending which arrives first, the later transaction has to wait till the first one finishes to complete. These locks are about SQL commands and which commands can run concurrently with the others. There's a graph here of how that looks like https://pankrat.github.io/2015/django-migrations-without-dow...

Usually for maximum performance (minimum latency, maximum throughput) you want to have operations not lock each other, unless absolutely necessary, in which case you want them to be short.

whilenot-dev•11mo ago
You make it sound like the conflict is just affecting performance and won't result in a deadlock. So it's for performance aware postgres clients/users, and not for postgres developers?
andyferris•11mo ago
It is a guide for developers using postgres as a client, who need to write systems that don't deadlock, are performant and are correct. These are the (rather sharp) tools that postgres provides for doing so (or else you can use e.g. serializable isolation and optimistic concurrency, but in my experience that has too many false positives and bail out rather eagerly, whereas these tools let you be very precise and granular).
mebcitto•11mo ago
Other relevant talks/blogs that I found really useful for understanding Postgres locks are:

* Unlocking the Postgres Lock Manager by Bruce Momjian: https://momjian.us/main/writings/pgsql/locking.pdf

* Anatomy of table-level locks by Gulcin Yildirim Jelinek: https://xata.io/blog/anatomy-of-locks

pasxizeis•11mo ago
Shameless plug: I wrote a tool[1] that executes a given migration against a test database (e.g. in your CI) and reports back what locks it acquired.

The rationale being to have a "lock diagnostics report" commented in your PR's migration file.

It's a prototype and has a few rough edges and missing functionality, but feedback is more than welcome.

[1] https://github.com/agis/pglockanalyze

jononor•11mo ago
Very practical! Locking is one of the things that can really bite when doing migrations.