frontpage.
newsnewestaskshowjobs

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•1y ago

Comments

jimbokun•1y 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•1y 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•1y ago
Not necessarily, I see native speakers completely ignore this a lot.

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

kreetx•1y 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•1y 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•1y ago
I prefer "ess queue ell" these days, but the first DBA I ever worked with pronounced it "squirrel".
gopalv•1y 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•1y ago
This is really great!!
gavinray•1y 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•1y 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•1y 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•1y 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•1y ago
This is a SQL to X library, though. I don’t think it’s what you need.
gavinray•1y 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.
KyleBrandt•1y 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.

genai-analyst•1y 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.

Claude Fable 5

https://www.anthropic.com/news/claude-fable-5-mythos-5
556•Philpax•1h ago•326 comments

Apple decided not to roll out Siri in EU after denied request for exemption

https://www.reuters.com/business/apple-failed-make-its-ai-tool-comply-eu-regulations-eu-commissio...
131•flanged•1h ago•249 comments

System Card: Claude Fable 5 and Claude Mythos 5 [pdf]

https://www-cdn.anthropic.com/d00db56fa754a1b115b6dd7cb2e3c342ee809620.pdf
133•scrlk•1h ago•32 comments

Making Graphics Like it's 1993

https://staniks.github.io/articles/catlantean-3d-blog-1/
537•sklopec•7h ago•81 comments

A giant star may have destroyed itself in one of the rarest explosions

https://phys.org/news/2026-05-giant-star-destroyed-universe-rarest.html
52•wglb•20h ago•9 comments

Microsoft's open source tools were hacked to steal passwords of AI developers

https://techcrunch.com/2026/06/08/microsofts-open-source-tools-were-hacked-to-steal-passwords-of-...
448•raffael_de•10h ago•161 comments

Launch HN: Transload (YC P26) – Measuring freight items with CCTV

16•nils_spatial•1h ago•4 comments

Where is the AI jobs crisis?

https://www.apollo.com/wealth/the-daily-spark/where-is-the-ai-jobs-crisis
13•bwestergard•30m ago•7 comments

Biff.core: system composition for Clojure web apps

https://biffweb.com/p/core/
30•jacobobryant•1h ago•7 comments

The LD_DEBUG environment variable (2012)

https://bnikolic.co.uk/blog/linux-ld-debug.html
4•tanelpoder•30m ago•0 comments

Is Grep All You Need? How Agent Harnesses Reshape Agentic Search

https://arxiv.org/abs/2605.15184
68•Anon84•4h ago•30 comments

Can LLMs Beat Classical Hyperparameter Optimization Algorithms?

https://arxiv.org/abs/2603.24647
61•galsapir•2h ago•8 comments

OpenCV 5 Is Here: The Biggest Leap in Years for Computer Vision

https://opencv.org/opencv-5/
547•ternaus•3d ago•101 comments

'Sloppenheimer:' Amazon Employees Mock the Company's AI on Slack

https://www.404media.co/sloppenheimer-amazon-employees-mock-the-companys-ai-on-slack/
128•doener•1h ago•64 comments

Show HN: GentleOS – A pair of hobby OSes for vintage 32-bit and 16-bit PCs

https://github.com/luke8086/gentleos32
49•luke8086•2d ago•75 comments

Unified Controllable and Faithful Text-to-CAD Generation with LLMs

https://arxiv.org/abs/2604.19773
37•PaulHoule•3h ago•6 comments

Let's Encrypt bans certificate usage in any US sanctioned territory [pdf]

https://letsencrypt.org/documents/LE-SA-v1.7-June-04-2026-diff.pdf
126•piskov•19h ago•92 comments

Emerge Career (YC S22) Is Hiring a Founding Growth Marketer

https://www.ycombinator.com/companies/emerge-career/jobs/v0S1AEG-founding-growth-marketer
1•gabesaruhashi•5h ago

Show HN: Gravity – interactive solar-system simulator, from Newton to Einstein

https://qunabu.github.io/Gravity/
89•qunabu•6h ago•22 comments

The iPhone's Last Stand?

https://stratechery.com/2026/the-iphones-last-stand/
116•swolpers•7h ago•159 comments

FCC wants to kill burner phones by forcing telecoms to get all customers' IDs

https://www.404media.co/fcc-wants-to-kill-burner-phones-by-forcing-telecoms-to-get-all-customers-...
165•berlianta•2h ago•112 comments

Show HN: Learn from 30 historical figures, open source, nonprofit, self-hosted

https://github.com/chipmates/agoracosmica
11•micstradev•6h ago•2 comments

Forever Young: how one molecule can lock plants in a youthful state (2025)

https://omnia.sas.upenn.edu/story/biologist-scott-poethig-plants-never-age
105•bryanrasmussen•9h ago•62 comments

What it feels like to work with Mythos

https://www.oneusefulthing.org/p/what-it-feels-like-to-work-with-mythos
19•swolpers•42m ago•8 comments

Using Optical Aberrations to Distinguish Real Astronomical Transients

https://arxiv.org/abs/2606.08319
18•solarist•2h ago•1 comments

Painting the Internet: A Different Kind of Warhol Worm [pdf]

https://cspages.ucalgary.ca/~aycock/papers/artworm.pdf
6•jruohonen•1d ago•0 comments

The Effective Sample Size

https://alex.smola.org/posts/40-effective-sample-size/
13•jxmorris12•4d ago•1 comments

Thi.ng – open-source building blocks for computational design and art

https://thi.ng
159•nmstoker•1d ago•20 comments

Cleaning up after AI rockstar developers

https://www.codingwithjesse.com/blog/rockstar-developers/
363•BrunoBernardino•8h ago•265 comments

An introduction to functional analysis for science and engineering

https://arxiv.org/abs/1904.02539
94•Anon84•2d ago•13 comments