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.

OpenAI and Hugging Face address security incident during model evaluation

https://openai.com/index/hugging-face-model-evaluation-security-incident/
1401•mfiguiere•18h ago•942 comments

Introduction to Formal Verification with Lean Part 1

https://hashcloak.com/blog/tutorial-introduction-to-formal-verification-with-lean-(part-1)
146•badcryptobitch•2d ago•15 comments

Kimi K3 Is Competitive with Fable; Kimi K3 and Fable Is SoTA

https://fireworks.ai/blog/kimik3-fable
777•piotrgrabowski•15h ago•400 comments

10 REM"_(C2SLFF4

https://beej.us/blog/data/mystery-comment/
38•ingve•2h ago•7 comments

Cornell's Interactive Wall of Birds

https://academy.allaboutbirds.org/features/wallofbirds/?_hsmi=428996456
33•yareally•3d ago•10 comments

Intel Starts Shipping High-NA EUV Silicon

https://morethanmoore.substack.com/p/intel-starts-shipping-high-na-euv
169•zdw•3d ago•60 comments

Original Apollo 11 Guidance Computer source code for command and lunar modules

https://github.com/chrislgarry/Apollo-11
123•noteness•9h ago•38 comments

Advertise in ChatGPT

https://ads.openai.com/
959•montecarl•19h ago•734 comments

Why do you suck at juggling now?

https://pgadey.ca/notes/suck-at-juggling/
34•surprisetalk•1w ago•21 comments

FreeInk: Open ecosystem for e-readers

https://freeink.org/
651•FriedPickles•19h ago•137 comments

Judge approves $1.5B Anthropic settlement for pirated books used to train Claude

https://apnews.com/article/ai-anthropic-copyright-settlement-claude-books-bartz-74b140444023898ae...
478•BeetleB•19h ago•445 comments

AMD Ryzen 7 7700X3D Review: 3D V-Cache Gaming Performance for Less – HotHardware

https://hothardware.com/reviews/amd-ryzen-7-7700x3d-gaming-cpu-review
37•rbanffy•3d ago•36 comments

Businesses with ugly AI menu redesigns

https://blog.fiddery.com/businesses-with-ugly-ai-menu-redesigns/
95•speckx•1h ago•71 comments

OverpAId – Fire your CEO. Hire the future

https://overpaid.lol
506•ignaloidas•3h ago•232 comments

Back to Kagi

https://blog.melashri.net/micro/back-to-kagi/
108•speckx•1h ago•88 comments

Gemini 3.6 Flash, 3.5 Flash-Lite, and 3.5 Flash Cyber

https://blog.google/innovation-and-ai/models-and-research/gemini-models/gemini-3-6-flash-3-5-flas...
728•logickkk1•23h ago•549 comments

Late.sh – a command-line Clubhouse for computer people

https://late.sh/
249•itherseed•12h ago•88 comments

Never Enough

https://dark.ronacher.eu/2026/7/21/never-enough/
118•reasonableklout•11h ago•40 comments

A digestion of the Jacobian conjecture counterexample

https://terrytao.wordpress.com/2026/07/21/a-digestion-of-the-jacobian-conjecture-counterexample/
292•jeremyscanvic•17h ago•120 comments

ScreenWall – Turn old phones into synced widgets for your space

https://screenwall.app/
74•buibuibui•5d ago•27 comments

Ten Steps Towards Happiness (2015)

http://hintjens.com/blog:99
183•emerongi•13h ago•82 comments

Jack Dorsey launches Buzz to combine team chat, AI agents and Git hosting

https://runtimewire.com/article/jack-dorsey-block-buzz-team-chat-ai-agents-git
352•ryanmerket•21h ago•311 comments

Long presumed dead, a thriving coral reef is discovered in West Africa

https://e360.yale.edu/digest/benin-coral-reef
373•speckx•22h ago•85 comments

"Drawing" the Mona Lisa with GPT-5.6, Claude, Gemini, and Grok

https://www.tryai.dev/blog/ai-drawing-arena-colored-pencils-claude-gpt-grok
229•hershyb_•17h ago•81 comments

It's a shame what's happened to radio

https://blog.jimgrey.net/2026/07/21/its-a-shame-whats-happened-to-radio-3/
169•sonicrocketman•15h ago•188 comments

Apple defeats liability for not scanning iCloud for CSAM

https://blog.ericgoldman.org/archives/2026/07/apple-defeats-liability-for-not-scanning-icloud-for...
439•speckx•1d ago•476 comments

Overload and insight look identical from the outside

https://pilgrima.ge/p/what-the-wire-knows
12•momentmaker•3d ago•1 comments

Laguna S 2.1

https://poolside.ai/blog/introducing-laguna-s-2-1
379•rexledesma•21h ago•70 comments

Map of the world's great castles and fortresses

https://thecastlemap.com/
294•marklit•22h ago•183 comments

Gemini last models: temperature, top_p, and top_k are deprecated and ignored

https://ai.google.dev/gemini-api/docs/latest-model
116•greatgib•17h ago•40 comments