Hacker News: hbirler

New comment by hbirler in "QueryBrew: System-Agnostic SQL-to-SQL Query Optimization [pdf]"

hbirler — Sat, 12 Sep 2026 00:36:34 +0000

Hello, paper co-author here. QueryBrew is based on our research relational database Umbra (https://umbra-db.com/) which has been in development since around 2018. Our optimizer needs to produce correct plans within milliseconds while considering thousands to millions of alternatives, so using machine learning based approaches is often not a great fit. We instead rely on purpose-built algorithms like query decorrelation (https://15799.courses.cs.cmu.edu/spring2025/papers/11-unnest...) and DP based join ordering (https://dl.acm.org/doi/pdf/10.1145/3183713.3183733). We have used AI for fuzzing input queries to test the optimizer.

New comment by hbirler in "I wrote a SQL engine in Python"

hbirler — Fri, 30 Dec 2022 21:57:06 +0000

A Python to SQL compiler already exists https://db.cs.uni-tuebingen.de/publications/2022/snakes-on-a...

New comment by hbirler in "NoJS – Creating a calculator with only HTML and CSS"

hbirler — Fri, 21 Jan 2022 23:38:41 +0000

Multiplying the 32bit floats 99999.0f and 9999.0f results in 999889984 (Firefox's result). So I guess this hints at what Firefox might be doing :)

Float multiplication's result: https://godbolt.org/z/q857f51GP

New comment by hbirler in "NoJS – Creating a calculator with only HTML and CSS"

hbirler — Fri, 21 Jan 2022 23:29:47 +0000

For 99999 x 9999:

Firefox 96 displays 999889984

Edge 97 displays 999890001

The answer should be 999890001, so Edge is right and Firefox is wrong