Top
Best
New

Posted by robbie-c 1 day ago

I rewrote PostHog's SQL parser, 70x faster, while barely looking at the code(posthog.com)
141 points | 69 comments
duendefm 1 day ago|
Well despite my current anti AI sentiment, I have to admit that after reading the article, It was a good use of AI, done by someone with good technical skills. Still I have the feeling that this only works because of the vast accumulated knowledge pre-AI, and if everybody keeps going in this path, it will end up making everyone not advancing their knowledge at the pace they did before. I feel that this AI immersion is really about selling our soul to the devil for short term gains.
bitlad 1 day ago||
I think AI is powertool. Period. If you give it to people who are skill, it will create a mess.

I think democratization of intelligence is going to be interesting. You could say the same with same about internet. I think it is part of evolution. May be intelligence or expertise is what does not make us special. May be it is that we are ingenious amd creative with tools and thats how we evolve.

steve_adams_86 1 day ago|||
> democratization of intelligence

I'm not trying to be pedantic; I think this is an interesting topic and there's a worthwhile distinction to make here. It isn't really being democratized for a couple reasons (at least).

One, access to information isn't truly knowledge in and of itself. People allowing information from LLMs to pass through their brains are not necessarily retaining any of it, and their ability to synthesize and utilize disparate information from LLMs isn't inherently improved by this technology. So the premise of knowledge isn't very sturdy in my mind.

Two, LLMs function across very broad fields of capability, accuracy, content, and so on, and the best models are not accessible to many people. I find people tend to mean the technology is widely available and accessible when they say 'democratization', but that's not necessarily true nor what that word means to begin with.

True democratization would mean something more like "everyone participates in, shapes, regulates, and grows this technology with their own inputs". I don't think that's what happens at all, and in fact, it has been quite the inversion of that so far.

I mention all of this because I agree that it will be interesting to watch what happens, but I don't agree that it will be for the same reasons. I worry about it specifically because there is not an egalitarian distribution of knowledge, and it is not democratically built or shared.

choilive 1 day ago||||
There are some studies that suggest human brain sizes have been shrinking over the last 20,000 years. The theory is that as civilization developed the demand for individual humans to be independently intelligent has weakened because we developed a "collective brain" and also self-domesticated to be more cooperative.
veidelis 1 day ago||
Honestly there might be truth to it, I don't get the downvotes - why?
Someone 1 day ago||
The correlation between brain volume and intelligence is fairly weak. Neanderthals had larger brains than humans, for example. Looking outside the hominids, we have fairly smart corvids with relatively tiny brains.

That means the chain of thought “brains volume decreased, so individuals must have gotten less intelligent. Yet, societies grew smarter, so there must be herd intelligence” breaks at “so individuals must have gotten less intelligent”.

I think/guess that argument may have merit when replacing brain volume by number of neurons (https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...)

_aavaa_ 1 day ago||
Even if we grant your argument that brain volume between species isn’t good proxy for intelligence, It doesn’t immediately hold for comparisons within a specie.
Someone 16 hours ago||
No, but correlations there aren’t large, either, if they exist.

Einstein’s brain reportedly was below average size.

That’s a n = 1 example, but there also is a 50/50 example: man vs women. on average, the brains of males are about 10% larger than those of women (https://en.wikipedia.org/wiki/Neuroscience_of_sex_difference...). That doesn’t show up in intelligence differences (https://en.wikipedia.org/wiki/Sex_differences_in_intelligenc...)

Even only looking at males or females, I don’t think larger (fe)males tend to be more intelligent.

ekidd 1 day ago|||
> May be it is that we are ingenious amd creative with tools and thats how we evolve.

And every time you use the AI to be ingenious or creative, that will be added to the training data. Then someday the AI can be ingenious and creative without you! (It might take a few more breakthroughs. But investors will literally spend trillions chasing those breakthroughs.)

The endgame here is to replace all human intelligence and labor with machines that are smarter and work cheaper. But who controls the machines?

bitlad 1 day ago||
> And every time you use the AI to be ingenious or creative, that will be added to the training data That's part of evolution.

We as humans have always outsmarted the tools.

nijave 22 hours ago|||
It is a tool for some and a crutch for others
Daishiman 1 day ago|||
> till I have the feeling that this only works because of the vast accumulated knowledge pre-AI

I'm not about to say that there's nothing new under the sun, but parsers are a really well-understood problem where 99.9% of people don't need frontier knowledge and wouldn't be in a position to use it anyway.

And I don't think that people doing research on parsers would ever rely on LLMs for precisely that reason. But we're not parser researchers right?

duendefm 1 day ago||
My point is, we have programming languages like C and C++, we have operating systems like Linux and FreeBSD, we have an empire of software and knowledge accumulated because of the intellectual battles fought by people before AI. With AI, we all are getting our coding easier (and are kind of being forced to), in a way that we will skip these kind of battles. That is, if we all use AI to make our job easier it will have some short term gain but we will end up as a whole ceasing to advance human knowledge with new stuff that has to come from real intellectual work. Like, I don't see people coming up with new outstanding technology if we all sucumb to be AI dependent.
Daishiman 1 day ago||
I'm not really sure that I agree. The LLM paradigm basically allows for the same development techniques, for better or worse, but amplified.

So if you were lazily copying the first blog result in Google, getting the first answer from an LLM is equivalent, but the output is actually likely to be better.

If you wanted to do your research on various techniques and evaluate alternatives, LLMs can amplify your capacity to research and to have specific considerations for your specific problem.

LLMs aren't going to solve people's natural inclination towards laziness.

Additionally, while it's true that people may read and learn less about the "lower" levels of software plumbing, it enables enormous possibilities of higher level thinking that before were limited by the amount of manpower you needed.

For example, with LLMs I can try different test sharding strategies or trivially change from factories to fixtures in large test suites. This would have been busywork or drudgery; now I can evaluate several architectural solutions which would not have been possible before.

jimbokun 1 day ago||
That can be said for any technology in history that made work easier.

“Whoa slow down with this ‘writing’ technology. No one will ever remember anything if they can just write it down.”

cespare 20 hours ago||
> We didn't write this parser by hand because, at least pre-AI-coding, parsers were extremely difficult to maintain. Writing one without AI would have taken months [...]

> Instead, we use ANTLR, a state-of-the-art, open source parser generator.

I don't agree with this (pre-AI-coding) take. Hand-rolled parsers are much easier to write well and maintain than people think. They also tend to be much faster and produce much better errors than parser generators. I guess if the language you're trying to parse is, say, C++, then you're going to have a miserable time (probably no matter what). But an SQL parser is very doable. (I say this as the author and maintainer of an in-house SQL dialect thingy at work.)

What makes building and maintaining a hand-written parser such a tractable task is:

- The code size can be large, but you can start with a core of a few well-chosen abstractions and then you add lots of parsing code for various language constructs but it's all kind of orthogonal and doesn't add compounding complexity as you go. - It's just about the most testable kind of code there is. You can cover all the various corner cases with tests and really lock in the behavior so that you can very confidently make changes. One approach I like is to make zillions of tiny test files in the target language accompanied by some golden representation of the AST.

And of course, as the author found out, these properties make writing a parser a really good task for AI coding, too. These tools are very, very good at generating a bunch of new code based on existing abstractions and covering it with lots of test cases.

So I agree with where they ended up, just not where they started :)

robbie-c 11 hours ago||
That's valid criticism, I kinda hand-waved the "months" part. I read everything I could about parsers while building this (I have a CS background but hadn't thought about parsers in a long time) and came across this blog post https://lakesail.com/blog/sql-parser-in-one-week/ which talked about building a toy parser in a week, so I scaled that up to months for a production one.
larodi 14 hours ago||
Well… tis difficult if one does not understand how grammars work, and therefore parsers. But we’ve seen people use stuff like ContextFreé’s Design Grammar, without even being IT guys, and still figure themselves around.

The whole notion grammars are hard is just wrong. They are not only powerful, but super simple in fact. As is the basic regexp if one cares to spend a focused afternoon to understand it. Probably even less time if working with a decent teacher.

jakewins 1 day ago||
I’ve had very good success in similar setups where you have some sort of “oracle” and can generate enormous corpuses of test data, such that you really, really trust the LLM code must work for the inputs you expect it’ll ever need to handle.

Makes me think of all the algorithms we specify in proof languages and then hand-implement in production languages - this setup could maybe let you just specify the proof of an algorithm and then let LLMs derive efficient implementations with the (slow) proof as an oracle

theLiminator 1 day ago||
This is the type of problem for which LLM generation is great for.

If you have an oracle, and your problem is largely just a pure function, it's pretty good at generating something that both works and is fast.

mikkelam 1 day ago||
I cannot believe they're sticking to their guns on this website design. It's awful.
joshmarinacci 1 day ago||
I love that it doesn't feel like every other vibe coded VC backed startup.
pixel_popping 1 day ago|||
They have an excellent branding and have some balls to pull it off, it shows passion, I highly trust it even in company settings.
kg 1 day ago|||
Try clicking 'switch to website mode' on the left side
nektro 1 day ago||
thank you!
my-next-account 1 day ago|||
It's awesome!
softboyled 1 day ago|||
Yeah. It locked up my browser. What a pile.
noja 1 day ago||
I love it. So different. Slightly BeOS.
jamestexas 6 hours ago||
This is super cool, and I am totally going to glean from how you handled testing some of this.

I have a tool I make as a data-plane to a graph engine, and it uses cap'n proto to help (And sqlite as a sort've IPC option). One of the biggest things I have is, I know I am not testing all of it to completion. I am not even really fuzzing, yet.

Thanks for sharing!

justAnotherHero 1 day ago||
That's great but I really wish you guys would do something about the llm integration, I tried using it two days ago to create a cohort of users using a sql query, and I was surprised to see that it said that it could not create cohorts for me and i had to resort to exporting data from a sql insight as a cohort cannot use a sql query. However the worst part was it just writing in the text input slowed down my m4 pro chip to less than 1 fps after 2 prompts and it really left a bad taste in my mouth.

Perhaps the next target for a 100x improvement

russellthehippo 1 day ago||
The key parts of this is how not vibecoded it is. Feels like a model of how you should do software with AI. Now that we can easily set up property testing, fuzzing, etc. there's almost no reason not to.
spullara 1 day ago|
that is vibecoding these days
keeda 1 day ago||
A while ago I had predicted that eventually all coding would eventually become vibe-coding but it would still be a deep engineering discipline (https://news.ycombinator.com/item?id=48040206) -- this is what I meant. Deep technical expertise is still needed, but it shifts from working with the code directly to crafting bespoke comprehensive validation mechanisms around the code. This is a great example of what that could look like.

So it's technically vibe-coding in the sense you don't really look at the code, you just look at the results and "go by the vibes"... except now you're working to rigorously quantify and enforce those vibes. (Philosophical aside: once vibes are rigorously enforced are they "vibes" anymore?)

ndr 1 day ago|
Great loop spotting!

Recently I was messing around with parquet files in Python and ended up needing to ship the results on Windows, without a Windows machine to test on.

Shipping Python to end users is half mad already, and doing it on Windows is exactly the kind of thing I don't want to spend my life maintaining.

So I figured I'd rewrite it in Go. But that meant embedding a DLL, and how would I test it? I could spin up a VM, sure. But GitHub Actions already has a Windows environment, and there was my loop: let the agent push to the repo, run tests in GHA, rinse and repeat.

In under an hour it had a full rewrite of my Python, passing every test and producing row-for-row copies of my Parquet output. And it does work on the user machine!

Spotting a loop like that is as satisfying as noticing you can walk your chess opponent into a smothered mate. Truly empowering.

nijave 22 hours ago|
DuckDB

Also Windows used to have a free VHD with a trial license you could download (and convert to different format with qemu-img)

ndr 14 hours ago||
I do consume the parquets with DuckDB but had to read in firebird sql stuff.

I didn't think of checking, but I now learnt there's an extension for DuckDB but it's C++ and also embeds the same DLL [0] https://github.com/flozer/duckdb-firebird

More comments...