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.

GPT‑Live

https://openai.com/index/introducing-gpt-live/
210•logickkk1•1h ago•136 comments

Chatto is now Open Source

https://www.hmans.dev/blog/chatto-is-open-source
287•speckx•2h ago•57 comments

Mistral's Robostral Navigate: a state of the art robotics navigation model

https://mistral.ai/news/robostral-navigate/
260•ottomengis•3h ago•59 comments

Decoding the obfuscated bash script on a Uniqlo t-shirt

https://tris.sherliker.net/blog/obfuscated-self-evaluating-bash-script-by-cdn-akamai-being-suppli...
1059•speerer•9h ago•180 comments

SWE-1.7 Reach Near GPT 5.5 and Opus Intelligence

https://cognition.com/blog/swe-1-7
98•mekpro•1h ago•67 comments

Cloudflare Meerkat - Globally distributed consensus

https://blog.cloudflare.com/meerkat-introduction/
143•bobnamob•4h ago•26 comments

EU now one step away from reviving private message scanning rules

https://cyberinsider.com/eu-now-one-step-away-from-reviving-private-message-scanning-rules/
50•ggirelli•1h ago•3 comments

GitLost: We Tricked GitHub's AI Agent into Leaking Private Repos

https://noma.security/blog/gitlost-how-we-tricked-githubs-ai-agent-into-leaking-private-repos/
448•ColinEberhardt•12h ago•172 comments

OpenBSD has a use-after-free allowing local privilege escalation to root

https://nvd.nist.gov/vuln/detail/cve-2026-57589
144•linggen•4h ago•74 comments

Show HN: Follow London Trains in 3D

https://ride.nexttrain.london/
75•mgranados•4d ago•29 comments

Show HN: Microsoft releases Flint, a visualization language for AI agents

https://microsoft.github.io/flint-chart/#/
3•chenglong-hn•19m ago•1 comments

EVE Online's Carbon engine is now open source: Fenris Creations explains why

https://www.gamesindustry.biz/eve-onlines-carbon-engine-is-now-open-source-fenris-creations-expla...
287•Stevvo•4d ago•98 comments

Show HN: Kastor – Terraform-style specs for AI agents

https://github.com/weirdGuy/kastor
27•weirdguy•2h ago•13 comments

Apple to increase spend with Broadcom to produce billions more U.S. chips

https://www.apple.com/newsroom/2026/07/apple-to-increase-spend-with-broadcom-to-produce-billions-...
237•soheilpro•6h ago•185 comments

TypeScript 7

https://devblogs.microsoft.com/typescript/announcing-typescript-7-0/
97•DanRosenwasser•1h ago•16 comments

Japan's Hayabusa2 probe to conduct flyby of Torifune asteroid

https://www3.nhk.or.jp/nhkworld/en/news/20260705_01/
115•dvh•3d ago•14 comments

TabFont – guitar tabs rendered as you type

https://philatype.com/tabfont/
35•ChrisArchitect•3d ago•6 comments

NoiseLang: Where N = 5 is a Dirac delta

https://manualmeida.dev/articles/noiselang/
85•manucorporat•2d ago•40 comments

How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)

https://neil.computer/notes/how-to-setup-minimal-zfs-nas-without-truenas/
303•4diii•14h ago•207 comments

Geosql: A Claude/Codex skill for geospatial data

https://github.com/dekart-xyz/geosql
102•rzk•9h ago•13 comments

Tenda firmware (multiple versions) contains hidden authentication backdoor

https://kb.cert.org/vuls/id/213560
319•miniBill•17h ago•110 comments

Chat Control 1.0 and 2.0 Explained

https://fightchatcontrol.eu/chat-control-overview
855•gasull•1d ago•328 comments

Every postcard tells a story

https://observer.co.uk/style/features/article/every-postcard-tells-a-story
24•NaOH•2d ago•19 comments

Structure and Interpretation of Computer Programs Video Lectures (1986)

https://ocw.mit.edu/courses/6-001-structure-and-interpretation-of-computer-programs-spring-2005/v...
288•gjvc•18h ago•40 comments

Copy That Floppy – Cambridge guide for preserving data from fragile floppy disks

https://www.digipres.org/the-floppy-guide/
159•whiteblossom•14h ago•61 comments

Ants: Who looks after the injured in a colony?

https://www.uni-wuerzburg.de/en/news-and-events/news/detail/news/ameisen-kolonie-verletzte-pflegt/
87•hhs•4d ago•41 comments

Catastrophe theory; geniuses and maniacs (2011)

http://glassbottomblog.blogspot.com/2011/01/catastrophe-theory-geniuses-and-maniacs.html
10•mbustamanter•3d ago•1 comments

GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup

https://www.gao.gov/products/gao-26-108193
262•Jimmc414•19h ago•139 comments

Canada's only watchmaking school still ticking after 80 years

https://www.cbc.ca/news/canada/montreal/canada-s-only-watchmaking-school-9.7254211
231•throw0101a•4d ago•131 comments

Home made GPU escalated quickly [video]

https://www.youtube.com/watch?v=qMR3IXF2sWw
158•erichocean•3d ago•50 comments