from Hacker News

/dev/null is an ACID compliant database

by swills on 10/23/25, 9:28 PM with 171 comments

  • by jihadjihad on 10/24/25, 1:25 AM

    In a similar vein, this is one of the most interesting things I’ve come across on HN over the years:

    https://www.linusakesson.net/programming/pipelogic/index.php

    Past HN post: https://news.ycombinator.com/item?id=15363029

  • by gchamonlive on 10/23/25, 11:09 PM

    Best stack cloud providers don't want you to know about, /dev/null for db and https://github.com/kelseyhightower/nocode for the backend.

  • by senfiaj on 10/24/25, 7:26 PM

    If Amazon used /dev/null instead of DynamoDB, we would not experienced such terrible outages.

  • by pyuser583 on 10/23/25, 10:19 PM

    I've used /dev/null for exactly this purpose. I have output that needs to go somewhere, and I don't want to worry about whether that somewhere can handle it.

    Later on in deployment, it will go somewhere else. Somewhere that has been evaluated for being able to handle it.

    In that way, /dev/null is to storage what `true` is to execution - it just works.

  • by cluckindan on 10/23/25, 10:09 PM

    Always instantly consistent, always available, and perfectly tolerant of partitioning.

    Truly, it is the only database which can be scaled to unlimited nodes and remain fully CAP.

  • by mjb on 10/24/25, 1:03 AM

    Best of all, /dev/null is also serializable (but not strict serializable) under many academic and textbook definitions.

    Specifically, these definitions require that transactions appear to execute in some serial order, and place no constraints on that serial order. So the database can issue all reads at time zero, returning empty results, and all writes at the time they happen (because who the hell cares?).

    The lesson? Demand real-time guarantees.

  • by magicalhippo on 10/24/25, 11:06 AM

    Reminds me of how in the math lectures, our professor would always point out he was ignoring the trivial solution[1].

    That /dev/null is ACID compliant is the trivial solution of databases.

    Still, a jolly good read, and a nice reminder that concepts like ACID don't exist in a vaccuum.

    [1]: https://en.wikipedia.org/wiki/Triviality_(mathematics)#Trivi...

  • by dd_xplore on 10/24/25, 3:36 PM

    One question though, if for some reason a poorely designed app discards data through /dev/null, is it tamper proof? Meaning can any other process or user access that information? (In runtime)

  • by tech234a on 10/24/25, 12:33 AM

    This reminds me of the S4 storage service: http://www.supersimplestorageservice.com/

    Discussed on HN a few times, but apparently not for a few years now: https://hn.algolia.com/?q=http%3A%2F%2Fwww.supersimplestorag...

  • by phendrenad2 on 10/24/25, 4:22 PM

    Reminds me of this classic highbrow techie banger

    https://en.wikipedia.org/wiki/Write-only_memory_(joke)

    See the datasheet also, I especially like the "insertions vs number of remaining pins" chart:

    https://web.archive.org/web/20120316141638/http://www.nation...

  • by qwm on 10/24/25, 4:20 PM

  • by jefftk on 10/24/25, 12:31 AM

    "The system transitions from one valid state to another" is clearly false: the system only has a single state.

  • by brunoborges on 10/24/25, 1:50 PM

    I get the joke, but IMO it doesn't pass Durability test, as what is sent to it (i.e. transactions) are not durable.

    Durability in ACID is about the durability of the data that is sent to the database (in this ironic post, /dev/null) once committed.

    "[...] completed transactions (or their effects) are recorded [...]"

    But I will give it that ACI do make sense!

    #PedanticMode

  • by rezonant on 10/23/25, 10:34 PM

    But is /dev/null web scale?

  • by vlowther on 10/24/25, 2:37 PM

    Before it was an ACID compliant database, it was also the fastest backup solution on the market: https://bofh.bjash.com/bofh/bofh1.html

  • by xandrius on 10/24/25, 9:53 AM

    Reminds me of mangodb: https://github.com/dcramer/mangodb

    The DB at cloud scale

  • by simultsop on 10/24/25, 4:28 AM

    You need an FAQ section, we have so many questions for this marvellous solution.

    Is it portable to all linux distros?

    Where is the ubuntu command to install it?

    What license does it use, is it free or else?

    Is it really open source or source only?

  • by taftster on 10/24/25, 4:53 PM

    Ah, how cute. An actual "old school" blog. Nostalgia. Tears in eyes.

    https://jyu.dev/blog/

    And the production of articles is about right too.

        . "Hello World" - The start of something great. [Dec 2024]

    . "Comparison is the Thief of Joy" - Link to another article. [Apr 2025]

    . "/dev/null is an ACID compliant database" - Funny, insightful. [Aug 2025]
    That read about like my blog 20 years ago.

    Funny post though, good read!

  • by hmokiguess on 10/23/25, 11:09 PM

    I guess it is also idempotent then

  • by theandrewbailey on 10/24/25, 1:09 AM

    /dev/null is the ultimate storageless function. It's like serverless, but for PII, and deployable anywhere!

  • by imcritic on 10/23/25, 10:27 PM

    How does a disaster recovery plan with it look like?

  • by jjrr1018 on 10/24/25, 3:19 PM

  • by yard2010 on 10/24/25, 6:20 AM

    I love vacously truths (not sure if this is how you say it in English)

    All the people I've met in London were androids.

  • by gunalx on 10/24/25, 9:47 AM

    You say it is always empty, but. I have seen weird issues coming from /dev/null not actually being empty but being a file or symlink (dont remember) With garbage data.

  • by amai on 10/24/25, 4:35 PM

    Can it rollback transactions?

  • by dzogchen on 10/24/25, 9:44 AM

    It's ACID compliant yes, but it is not a database.

  • by hshdhdhehd on 10/24/25, 2:40 AM

    It is also local first, low latency, data residency compliant, SOC2 compliant, zero dependency and webscale.

  • by raggi on 10/24/25, 5:58 AM

  • by novoreorx on 10/24/25, 5:22 AM

    What a weird title, you can say it's ACID but it's not a database

  • by 1970-01-01 on 10/23/25, 11:53 PM

    So if you could somehow get something stuck in /dev/null would it cause a panic or what happens?

  • by zdw on 10/24/25, 2:36 PM

    The RSS feed on this site is broken.

  • by yuppiemephisto on 10/24/25, 2:35 AM

    And the axiom of empty set is an inaccessible cardinal axiom

  • by keithnz on 10/24/25, 12:25 AM

    took a while to pipe my multi-terabyte db to /dev/null but now that I have I'm saving a ton of money on storage.

  • by sph on 10/24/25, 8:31 AM

    It's ACID compliant. But it's not a database.

  • by johnfn on 10/24/25, 12:45 AM

    Not only that, it provides all 3 components of CAP!

  • by BiraIgnacio on 10/24/25, 1:11 AM

    A strong business opportunity right there.

  • by layer8 on 10/24/25, 12:32 AM

    Not on Windows.

  • by bitwize on 10/24/25, 12:45 AM

    Yes, but does it support sharding? Sharding is the secret ingredient in the web scale sauce.

  • by idontwantthis on 10/23/25, 11:59 PM

    This reminds me of how I would write a HashCode implementation on intro CS exams in college:

    ‘return 5’

  • by luckystarr on 10/24/25, 10:27 AM

    Now make an algebra out of the CAP theorem. It's not already one, isn't it? Didn't read the paper.

  • by DeathArrow on 10/24/25, 5:38 AM

    More than that, /dev/null is infinitely scalable.

  • by Western0 on 10/24/25, 12:14 PM

    yes

  • by Perz1val on 10/24/25, 8:02 AM

    Don't forget to feed your void. `dd if=/dev/zero of=/dev/null bs=500M count=1`

  • by justinhj on 10/24/25, 3:39 AM

    Add an mcp server and I'm in

  • by dheera on 10/24/25, 2:15 AM

    I guess /dev/null is also an excellent source of investment advice, you are guaranteed to not lose money

  • by doublerabbit on 10/23/25, 11:39 PM

    Idea: NaaS. Null as a service.

  • by ramon156 on 10/24/25, 8:29 AM

    I'm gonna be that guy, tyop at the bottom

    > entreprise

  • by tonyhart7 on 10/24/25, 4:10 AM

    it looks promising but what about AI /dev/null usage????

  • by blourvim on 10/24/25, 2:12 AM

    I love this

  • by charcircuit on 10/23/25, 11:20 PM

    /dev/null is not a database. By this logic is a hard disk a database, is a CD a database. No. They are storage mediums. You could store a database on them, but they themselves are not a database.

    Considering there is no way to read back data written to /dev/null it will not be useful for storing database data.

  • by QuiCasseRien on 10/23/25, 10:38 PM

    Fast and easy to read, funny and fuckingly true !

    best post of the week ^^