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•10mo ago

Comments

jimbokun•10mo 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•10mo 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•10mo ago
Not necessarily, I see native speakers completely ignore this a lot.

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

kreetx•10mo 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•10mo 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•10mo ago
I prefer "ess queue ell" these days, but the first DBA I ever worked with pronounced it "squirrel".
gopalv•10mo 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•10mo ago
This is really great!!
gavinray•10mo 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•10mo 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•10mo 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•10mo 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•10mo ago
This is a SQL to X library, though. I don’t think it’s what you need.
gavinray•10mo 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•9mo 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•10mo 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.

Claude surpasses ChatGPT to become the #1 app on the US App Store

https://apps.apple.com/us/iphone/charts
132•byincugnito•21m ago•32 comments

The Windows 95 user interface: A case study in usability engineering (1996)

https://dl.acm.org/doi/fullHtml/10.1145/238386.238611
82•ksec•2h ago•32 comments

MinIO Is Dead, Long Live MinIO

https://blog.vonng.com/en/db/minio-resurrect/
166•zufallsheld•3h ago•57 comments

We do not think Anthropic should be designated as a supply chain risk

https://twitter.com/OpenAI/status/2027846016423321831
107•golfer•3h ago•33 comments

Obsidian Sync now has a headless client

https://help.obsidian.md/sync/headless
361•adilmoujahid•7h ago•129 comments

The happiest I've ever been

https://ben-mini.com/2026/the-happiest-ive-ever-been
281•bewal416•2d ago•130 comments

The war against PDFs is heating up

https://www.economist.com/business/2026/02/24/the-war-against-pdfs-is-heating-up
17•pseudolus•1h ago•15 comments

Block the “Upgrade to Tahoe” Alerts

https://robservatory.com/block-the-upgrade-to-tahoe-alerts-and-system-settings-indicator/
105•todsacerdoti•5h ago•38 comments

Addressing Antigravity Bans and Reinstating Access

https://github.com/google-gemini/gemini-cli/discussions/20632
193•RyanShook•10h ago•155 comments

Verified Spec-Driven Development (VSDD)

https://gist.github.com/dollspace-gay/d8d3bc3ecf4188df049d7a4726bb2a00
138•todsacerdoti•7h ago•66 comments

Deterministic Programming with LLMs

https://www.mcherm.com/deterministic-programming-with-llms.html
8•todsacerdoti•3d ago•2 comments

Woxi: Wolfram Mathematica Reimplementation in Rust

https://github.com/ad-si/Woxi
232•adamnemecek•3d ago•101 comments

Qwen3.5 122B and 35B models offer Sonnet 4.5 performance on local computers

https://venturebeat.com/technology/alibabas-new-open-source-qwen3-5-medium-models-offer-sonnet-4-...
160•lostmsu•4h ago•105 comments

Building a Minimal Transformer for 10-digit Addition

https://alexlitzenberger.com/blog/post.html?post=/building_a_minimal_transformer_for_10_digit_add...
25•kelseyfrog•2h ago•4 comments

New evidence that Cantor plagiarized Dedekind?

https://www.quantamagazine.org/the-man-who-stole-infinity-20260225/
103•rbanffy•3d ago•66 comments

Show HN: Xmloxide – an agent made rust replacement for libxml2

https://github.com/jonwiggins/xmloxide
4•jawiggins•45m ago•0 comments

Werner Herzog Between Fact and Fiction

https://www.thenation.com/article/culture/werner-herzog-future-truth/
60•Hooke•1d ago•12 comments

Show HN: Now I Get It – Translate scientific papers into interactive webpages

https://nowigetit.us
173•jbdamask•11h ago•98 comments

The whole thing was a scam

https://garymarcus.substack.com/p/the-whole-thing-was-scam
543•guilamu•7h ago•155 comments

The archivist preserving decaying floppy disks

https://www.popsci.com/technology/floppy-disk-archivist-project/
42•Brajeshwar•3d ago•4 comments

747s and Coding Agents

https://carlkolon.com/2026/02/27/engineering-747-coding-agents/
117•cckolon•1d ago•55 comments

Pentagon chief blocks officers from Ivy League schools and top universities

https://fortune.com/2026/02/28/pentagon-officer-education-ivy-league-schools-universities-partner...
18•geox•38m ago•2 comments

Ghosts'n Goblins – “Worse danger is ahead”

https://superchartisland.com/ghostsn-goblins/
57•elvis70•3d ago•24 comments

From Noise to Image – interactive guide to diffusion

https://lighthousesoftware.co.uk/projects/from-noise-to-image/
98•simedw•2d ago•15 comments

Stop Burning Your Context Window – How We Cut MCP Output by 98% in Claude Code

https://mksg.lu/blog/context-mode
205•mksglu•14h ago•49 comments

What I learned while trying to build a production-ready nearest neighbor system

https://github.com/thatipamula-jashwanth/smart-knn
16•Jashwanth01•3d ago•7 comments

Unsloth Dynamic 2.0 GGUFs

https://unsloth.ai/docs/basics/unsloth-dynamic-2.0-ggufs
197•tosh•15h ago•51 comments

The Eternal Promise: A History of Attempts to Eliminate Programmers

https://www.ivanturkovic.com/2026/01/22/history-software-simplification-cobol-ai-hype/
224•dinvlad•3d ago•160 comments

The Future of AI

https://lucijagregov.com/2026/02/26/the-future-of-ai/
113•BerislavLopac•13h ago•89 comments

Our Agreement with the Department of War

https://openai.com/index/our-agreement-with-the-department-of-war
189•surprisetalk•3h ago•170 comments