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Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

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Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#681

Post by [deleted] »

wanderlust123 wrote: post #638
fg137 wrote: post #626

If you can do a Rust rewrite with AI, I can create one as well. What makes yours better than mine? Your decade long expertise in database or Rust language? Your reputation? Your proven track record to manage large, complex projects? Your time committed to the project? I don't see any of that. I don't know why anyone would choose this over the actively (community) maintained proper Postgres project.

There’s no claim being made that your rewrite cannot be better. He has provided benchmark results which provide a dimension amongst which to measure your rewrite. If you can do better by all means post your rewrite. Finally, these kind of projects can eventually over time become projects that are actively used. Postgres is not some entity that existed before the universe was created; it was also created by someone an…

[deleted]

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#682

Post by fg137 »

wkoszek wrote: post #662
fg137 wrote: post #626

If you can do a Rust rewrite with AI, I can create one as well. What makes yours better than mine? Your decade long expertise in database or Rust language? Your reputation? Your proven track record to manage large, complex projects? Your time committed to the project? I don't see any of that. I don't know why anyone would choose this over the actively (community) maintained proper Postgres project.

His project is cool. Students could use it as an example of porting code. Companies could switch to it, if it works. There are hundreds of reasons why people may want it, so it's awesome he's publishing one. Something needs to be done to get interest and then adoption.

Let me just point out:

The project is not cool. This is not a new idea, and there is nothing special.

Students won't use it as an example of porting code. I am not aware "porting code" is part of standard software engineering or computer science curriculum. That's not the kind of thing being taught in schools.

Companies won't switch to it unless their CTOs are either insane or incompetent.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#683

Post by satvikpendem »

queenkjuul wrote: post #317
satvikpendem wrote: post #12

Earlier quoted context omitted.

It is more and more the future. No human would want to rewrite one technology to another because it is too marginal a gain. AI on the other hand does not give a shit.

> No human would want to rewrite one technology to another Except for when they do, like the new TypeScript...

That was before good end to end models though, they started it in 2024 where it was in 2025 that models were capable of long term continuous work.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#684

Post by xyst »

it's a neat experiment, obviously inspired by the bun guy.

but given the author/maintainer is essentially unknown, I highly doubt this will reach it's target audience. But one thing I do agree with is that postgres is long overdue for a re-write into a memory safe language.

also any real swe with more than a few years of experience knows "100% of regression suite passing" doesn't mean anything other than a neat checkmark for C-level executives.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#685

Post by Keyframe »

ramijames wrote: post #651
Keyframe wrote: post #632

Earlier quoted context omitted.

I don't want to knock you down as most have already did. In-fact it's a useful exercise going forward in exploring how to work with AI. It's here, we're all going to use it one way or the other. Zero issues with that, in-fact kudos to going through the pain of it all. Now, having gone through several such endeavors originally myself, albeit with internal tools and systems (as an exercise), I've noticed that while all…

I'm curious. Do you attribute this to weak and/or incomplete tests? How granular should tests be to have complete coverage so that an AI won't create a converted codebase that "passes tests" but is still functionally inaccurate?

That's the million dollar question. Do you/we/us have tests that cover everything which covers QA as well? If such a mythical beast exists, maybe from remnants of ye olde TDD past and hasn't been modified as such.. then maybe this would be possible to do as such.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#686

Post by Keyframe »

jakswa wrote: post #652
Keyframe wrote: post #632

Earlier quoted context omitted.

I don't want to knock you down as most have already did. In-fact it's a useful exercise going forward in exploring how to work with AI. It's here, we're all going to use it one way or the other. Zero issues with that, in-fact kudos to going through the pain of it all. Now, having gone through several such endeavors originally myself, albeit with internal tools and systems (as an exercise), I've noticed that while all…

what model did you try it with? I agree and also push back a bit: How will we know when the LLMs reach the point of handling it if no one takes the leap? I applaud more people sludging through the slop and hauling their slop buckets around. An example is Fable being released. I felt like the most complex thing I was willing to sludge through was having it clone llama-server's web UI with my own opinions (I really lik…

Last time it was Opus 4.8 to no avail. Fable is too expen..precious to try that yet :)

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#687

Post by CamouflagedKiwi »

jiggawatts wrote: post #153
CamouflagedKiwi wrote: post #133

Earlier quoted context omitted.

I have some familiarity with the bank situation, and while a lot of them are on some very old systems (maybe COBOL, maybe something else, either way they want off it) the cost of actually re-writing the code is far from the most significant issue. Consider: You have a big mainframe running your tier 1 bank. Assume that you can see all the code on it, and you can feed all that to an LLM if you like. Getting it to spit…

> while you could ask your LLM to do that you aren't going to run your bank on the result. Why not? I feel like we're entering a new era of prejudice against not a category of humans, but against non-human intelligences. The design patterns for distributed and fault-tolerant systems are well-known and established in the industry. Both humans and AIs are familiar with them! So if you sketch a design for the AI to foll…

Because you know that the current one works. If you have a bank running on COBOL (or whatever), you've had that for 30+ years now, so while it might have bugs, you know what they are. You don't know what the LLM output is. Hence back to my original point: writing the code is not the hard bit. Making yourself (and your CEO etc) comfortable to put that into production is one of the hard bits.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#688

Post by film42 »

vanviegen wrote: post #591
film42 wrote: post #452

Earlier quoted context omitted.

You are correct! TIL, and thank you. Connection processes get a SIGQUIT, shared buffers cleared, and WAL replayed, but postmaster stays alive. It's effectively an online restart.

What's online about this restart? Just that the tcp port keeps listening? I assume all running transaction will have to be aborted, right? And connections dropped?

The postmaster is effectively your supervisor. It could see the child segfault and abort the whole DB, but that would be deferring supervision to your init system. Not ideal.

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#689

Post by SirHackalot »

addedGone wrote: post #635
munchler wrote: post #361

Earlier quoted context omitted.

> Code is code. It either does the job or doesn't. Surely that is not the only dimension that matters when evaluating software. Maintainability and readability, for example, are crucial for any long-lived project.

In the future, code readability will not really matter, the concept of maintainability will also change: Is it maintainable by AI, if yes, then it's maintainable, we will approach the day where we have virtually ZERO code written by human, so all the tools must be built for AIs, not humans anymore.

Perhaps in the future my grandmother will have wheels… But today radiologists still do radiology (despite AI being better at reading scans), taxi drivers still have work, and truck drivers are still able to put food on the table. It’s still 2026, time traveler, so touch grass…

Re: Postgres rewritten in Rust, now passing 100% of the Postgres regression tests

#690

Post by wtetzner »

HumblyTossed wrote: post #679
wtetzner wrote: post #656

Earlier quoted context omitted.

So your solution is to just read through all 1M+ lines of code?

And yours is to read through all 37000 commit messages?? don't be obtuse. Nobody needs to do either.

This was already addressed:

> But with LLMs generating 7101 commits in less than a month that isn't feasible.

I don't think trying to understand LLM generated code is feasible for anything other than very small projects. IMO it's a big problem with using LLMs for coding. Sure, they can generate a bunch of stuff, but in some ways that just makes the real problems of software development even harder.

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