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•8mo ago

Comments

jimbokun•8mo 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•8mo 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•8mo ago
Not necessarily, I see native speakers completely ignore this a lot.

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

kreetx•8mo 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•8mo 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•8mo ago
I prefer "ess queue ell" these days, but the first DBA I ever worked with pronounced it "squirrel".
gopalv•8mo 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•8mo ago
This is really great!!
gavinray•8mo 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•8mo 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•8mo 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•8mo 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•8mo ago
This is a SQL to X library, though. I don’t think it’s what you need.
gavinray•8mo 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•7mo 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•8mo 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.

What an unprocessed photo looks like

https://maurycyz.com/misc/raw_photo/
850•zdw•6h ago•171 comments

You can make up HTML tags

https://maurycyz.com/misc/make-up-tags/
109•todsacerdoti•2h ago•42 comments

Unity's Mono problem: Why your C# code runs slower than it should

https://marekfiser.com/blog/mono-vs-dot-net-in-unity/
147•iliketrains•7h ago•70 comments

MongoBleed Explained Simply

https://bigdata.2minutestreaming.com/p/mongobleed-explained-simply
144•todsacerdoti•8h ago•60 comments

As AI gobbles up chips, prices for devices may rise

https://www.npr.org/2025/12/28/nx-s1-5656190/ai-chips-memory-prices-ram
90•geox•6h ago•92 comments

Software engineers should be a little bit cynical

https://www.seangoedecke.com/a-little-bit-cynical/
139•zdw•7h ago•104 comments

Why I Think Valve's Retiring the Steam Deck LCD

https://gardinerbryant.com/why-valves-retiring-the-steam-deck-lcd/
14•Ariarule•1h ago•20 comments

Researchers discover molecular difference in autistic brains

https://medicine.yale.edu/news-article/molecular-difference-in-autistic-brains/
83•amichail•7h ago•59 comments

Spherical Cow

https://lib.rs/crates/spherical-cow
75•Natfan•6h ago•7 comments

PySDR: A Guide to SDR and DSP Using Python

https://pysdr.org/content/intro.html
152•kklisura•9h ago•7 comments

Growing up in “404 Not Found”: China's nuclear city in the Gobi Desert

https://substack.com/inbox/post/182743659
725•Vincent_Yan404•22h ago•321 comments

Show HN: My app just won best iOS Japanese learning tool of 2025 award (blog)

https://skerritt.blog/best-japanese-learning-tools-2025-award-show/
77•wahnfrieden•5h ago•14 comments

A bitwise reproducible deep learning framework

https://github.com/microsoft/RepDL
9•noosphr•6d ago•0 comments

Slaughtering Competition Problems with Quantifier Elimination (2021)

https://grossack.site/2021/12/22/qe-competition.html
43•todsacerdoti•6h ago•0 comments

Line scan camera image processing

https://daniel.lawrence.lu/blog/2025-09-21-line-scan-camera-image-processing/
5•vasco•3d ago•1 comments

62 years in the making: NYC's newest water tunnel nears the finish line

https://ny1.com/nyc/all-boroughs/news/2025/11/09/water--dep--tunnels-
102•eatonphil•6h ago•58 comments

Building a macOS app to know when my Mac is thermal throttling

https://stanislas.blog/2025/12/macos-thermal-throttling-app/
256•angristan•17h ago•109 comments

Why I Disappeared – My week with minimal internet in a remote island chain

https://www.kenklippenstein.com/p/why-i-disappeared
66•eh_why_not•7h ago•55 comments

Learn computer graphics from scratch and for free

https://www.scratchapixel.com
221•theusus•18h ago•26 comments

Finding Jingle Town: Debugging an N64 Game Without Symbols

https://blog.chrislewis.au/finding-jingle-town-debugging-an-n64-game-without-symbols/
14•knackers•5d ago•0 comments

How to Complain (2024)

https://outerproduct.net/trivial/2024-03-25_complain.html
44•ysangkok•6h ago•5 comments

Fast Cvvdp Implementation in C

https://github.com/halidecx/fcvvdp
20•todsacerdoti•5h ago•1 comments

Stepping down as Mockito maintainer after ten years

https://github.com/mockito/mockito/issues/3777
238•saikatsg•9h ago•147 comments

Remembering Lou Gerstner

https://newsroom.ibm.com/2025-12-28-Remembering-Lou-Gerstner
80•thm•10h ago•36 comments

No, it's not a battleship

https://www.navalgazing.net/No-its-not
120•hermitcrab•9h ago•155 comments

Writing non-English languages with a QWERTY keyboard

https://altgr-weur.eu/altgr-intl.html
22•tokai•4d ago•11 comments

One year of keeping a tada list

https://www.ducktyped.org/p/one-year-of-keeping-a-tada-list
248•egonschiele•6d ago•75 comments

C++ says “We have try. . . finally at home”

https://devblogs.microsoft.com/oldnewthing/20251222-00/?p=111890
112•ibobev•22h ago•125 comments

Rust errors without dependencies

https://vincents.dev/blog/rust-errors-without-dependencies/
39•vsgherzi•1d ago•63 comments

Time in C++: Inter-Clock Conversions, Epochs, and Durations

https://www.sandordargo.com/blog/2025/12/24/clocks-part-5-conversions
31•ibobev•3d ago•7 comments