frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

Anatomy of a SQL Engine

https://www.dolthub.com/blog/2025-04-25-sql-engine-anatomy/
168•ingve•6mo ago

Comments

jimbokun•6mo ago
Very nice write up enumerating all the stages of SQL query execution. Interesting even if you don’t care about the DoIt database specifically.
Austizzle•6mo ago
Man, this title tripped me up for a minute because I pronounce it with the letters like Ess-Queue-Ell

So the "A" in "A ess-queue-ell" engine felt like it should have been an "An" until I realized it was meant to be pronounced like "sequel"

perching_aix•6mo ago
Not necessarily, I see native speakers completely ignore this a lot.

Have you ever considered pronouncing it as squirrel by the way?

kreetx•6mo ago
Many (most?) non-native English speakers do pronounce it as ess-queue-ell, especially in their own languages, so yes, the use of "a" instead of "an" does look off from that perspective.
SloopJon•6mo ago
When I read SQL for Dummies almost thirty years ago, it made a point of distinguishing "sequel" as a historical predecessor to standard "SQL." As I recall, the author even asserted that SQL is not an acronym/initialism for structured query language. I felt funny saying sequel for the next decade or so, because I wasn't an old timer experienced with this pre-SQL technology.

Now I usually say sequel because everyone else does. That and it rolls off the tongue better than S-Q-L.

jtolmar•6mo ago
I prefer "ess queue ell" these days, but the first DBA I ever worked with pronounced it "squirrel".
gopalv•6mo ago
This is a great write up about a pull-style volcano SQL engine.

The IR I've used is the Calcite implementation, this looks very concept adjacent enough that it makes sense on the first read.

> tmp2/test-branch> explain plan select count() from xy join uv on x = u;

One of the helpful things we did was to build a graphviz dot export for the explains plans, which saved us days and years of work when trying to explain an optimization problem between the physical and logical layers.

My version would end up displayed as SVG like this

https://web.archive.org/web/20190724161156/http://people.apa...

But the calcite logical plans also have that dot export modes.

https://issues.apache.org/jira/browse/CALCITE-4197

th0ma5•6mo ago
This is really great!!
gavinray•6mo ago
Calcite also has a relatively-unknown web tool for plan visualization that lets you step through execution.

It's a method from "RuleMatchVisualizer":

https://github.com/apache/calcite/blob/36f6dddd894b8b79edeb5...

Here's a screenshot of what the webpage looks like, for anyone curious:

https://github.com/GavinRay97/GraphQLCalcite/blob/92b18a850d...

ignoreusernames•6mo ago
I recommend anyone who works with databases to write a simple engine. It's a lot simpler than you may think and it's a great exercise. If using python, sqlglot (https://github.com/tobymao/sqlglot) let's you skip all the parsing and it even does some simple optimizations. From the parsed query tree it's pretty straightforward to build a logical plan and execute that. You can even use python's builtin ast module to convert sql expressions into python ones (so no need for a custom interpreter!)
Abde-Notte•6mo ago
Second this - building even a simple engine gives real insight into query planning and execution. Once parsing is handled, the core ideas are a lot more approachable than they seem.
albert_e•6mo ago
Sorry for slight digression.

In a larger system we are building we need a text-to-sql capability for some structured data retrieval.

Is there a way one could utilize this library (sqlglot) to build a multi-dialect sql generator -- that is not currently solved by directly relying on a LLM that is better at code generation in general?

LtdJorge•6mo ago
This is a SQL to X library, though. I don’t think it’s what you need.
gavinray•6mo ago
You can use an LLM to generate query-builder expressions from popular libraries in whatever language.

For example, on the JVM there is jOOQ, which allows you to write something like:

  select(field("foo"), avg("bar")).from(table("todos"))
And then it will render dialect-specific SQL. It has very advanced emulation functionality for things like JSON aggregations and working around quirks of dialects.

Alternatively, you can ask an LLM to generate a specific dialect of SQL, and then use jOOQ to parse it to an AST, and then render it as a different dialect, like:

    val parser= DSL.using(SQLDialect.POSTGRES).parser()
    val parsedQuery = parser.parseQuery(postgresQuery)
    val renderedMySQL = DSL.using(SQLDialect.MYSQL).renderInlined(parsedQuery)
    println(renderedMySQL)
Unsure if functionality like this exists in other Query Builder libraries for other languages.
genai-analyst•6mo ago
another digression here... sorry... i see you're trying to diy text-to-sql—at some point you're gonna hit a bunch of hiccups. like, the model writes a query that “almost” works but joins the wrong tables, or it assumes column names that don’t exist, or it returns the wrong agg because it misread the intent. and retries won’t always save you—it’ll just confidently hallucinate again.

we’ve been through all of that at wobby.ai we ended up building a system where the data team defines guardrails and reusable query templates, so the agent doesn’t just make stuff up. it can still handle user prompts, but within a safe structure. if you want to save yourself from debugging this stuff endlessly, might be worth checking out wobby.ai.

KyleBrandt•6mo ago
Using dolthub's go-mysql-server for Grafana's upcoming SQL expressions feature (private preview in Grafana 12, but in the OSS version with a feature toggle).

GMS lets you provide your own table and database implementations, so we use GMS to perform SQL queries against Grafana's dataframes - so users can join or manipulate different data source queires, but we don't have to insert the data into SQL to do this thanks to GMS.

Interactive World History Atlas Since 3000 BC

http://geacron.com/home-en/
87•not_knuth•2h ago•44 comments

CUDA Ontology

https://jamesakl.com/posts/cuda-ontology/
121•gugagore•3d ago•15 comments

Android/Linux Dual Boot

https://wiki.postmarketos.org/wiki/Dual_Booting/WiP
126•joooscha•3d ago•60 comments

Basalt Woven Textile

https://materialdistrict.com/material/basalt-woven-textile/
120•rbanffy•6h ago•62 comments

Show HN: Awesome J2ME

https://github.com/hstsethi/awesome-j2me
7•catstor•1h ago•3 comments

Europe is scaling back GDPR and relaxing AI laws

https://www.theverge.com/news/823750/european-union-ai-act-gdpr-changes
784•ksec•21h ago•881 comments

New Proofs Probe Soap-Film Singularities

https://www.quantamagazine.org/new-proofs-probe-soap-film-singularities-20251112/
18•pseudolus•1w ago•0 comments

Meta Segment Anything Model 3

https://ai.meta.com/sam3/
528•lukeinator42•19h ago•105 comments

Loose wire leads to blackout, contact with Francis Scott Key bridge

https://www.ntsb.gov:443/news/press-releases/Pages/NR20251118.aspx
357•DamnInteresting•16h ago•144 comments

Scientists Reveal How the Maya Predicted Eclipses for Centuries

https://www.sciencealert.com/scientists-reveal-how-the-maya-predicted-eclipses-for-centuries
10•rguiscard•6d ago•0 comments

AI is a front for consolidation of resources and power

https://www.chrbutler.com/what-ai-is-really-for
389•delaugust•17h ago•307 comments

Researchers discover security vulnerability in WhatsApp

https://www.univie.ac.at/en/news/detail/forscherinnen-entdecken-grosse-sicherheitsluecke-in-whatsapp
251•KingNoLimit•15h ago•95 comments

Building more with GPT-5.1-Codex-Max

https://openai.com/index/gpt-5-1-codex-max/
426•hansonw•18h ago•255 comments

#!magic, details about the shebang/hash-bang mechanism on various Unix flavours

https://www.in-ulm.de/%7Emascheck/various/shebang/
46•js2•7h ago•12 comments

Precise geolocation via Wi-Fi Positioning System

https://www.amoses.dev/blog/wifi-location/
196•nicosalm•14h ago•74 comments

Implementation of a Java Processor on a FPGA

https://mavmatrix.uta.edu/electricaleng_theses/337/
47•mghackerlady•5h ago•20 comments

What really happened with the CIA and The Paris Review?

https://www.theparisreview.org/blog/2025/11/11/what-really-happened-with-the-cia-and-the-paris-re...
69•frenzcan•1w ago•8 comments

Foliated Distance Fields [video]

https://www.youtube.com/watch?v=3AGeLuO5WdY
8•surprisetalk•6d ago•0 comments

Launch HN: Mosaic (YC W25) – Agentic Video Editing

https://mosaic.so
124•adishj•21h ago•118 comments

DOS Days – Laptop Displays

https://www.dosdays.co.uk/topics/laptop_displays.php
8•nullbyte808•3h ago•0 comments

CLI tool to check the Git status of multiple projects

https://github.com/uralys/check-projects
39•chrisdugne•6d ago•21 comments

PHP 8.5 gets released today, here's what's new

https://stitcher.io/blog/new-in-php-85
135•brentroose•6h ago•70 comments

How Slide Rules Work

https://amenzwa.github.io/stem/ComputingHistory/HowSlideRulesWork/
124•ColinWright•15h ago•29 comments

40 years ago, Calvin and Hobbes' raucous adventures burst onto the comics page

https://text.npr.org/nx-s1-5564064
10•mooreds•20m ago•0 comments

Static Web Hosting on the Intel N150: FreeBSD, SmartOS, NetBSD, OpenBSD and Linu

https://it-notes.dragas.net/2025/11/19/static-web-hosting-intel-n150-freebsd-smartos-netbsd-openb...
169•t-3•19h ago•64 comments

The Lucas-Lehmer Prime Number Test

https://www.scientificamerican.com/article/how-to-identify-a-prime-number-without-a-computer/
77•beardyw•1w ago•42 comments

Vortex: An extensible, state of the art columnar file format

https://github.com/vortex-data/vortex
84•tanelpoder•5d ago•21 comments

Gaming on Linux has never been more approachable

https://www.theverge.com/tech/823337/switching-linux-gaming-desktop-cachyos
444•throwaway270925•14h ago•329 comments

How to stay sane in a world that rewards insanity

https://www.joanwestenberg.com/p/how-to-stay-sane-in-a-world-that-rewards-insanity
240•enbywithunix•21h ago•186 comments

The patent office is about to make bad patents untouchable

https://www.eff.org/deeplinks/2025/11/patent-office-about-make-bad-patents-untouchable
498•iamnothere•14h ago•68 comments