Data Elixir

Data Elixir

@dataelixir.com

Data Elixir is a weekly newsletter with curated data science picks from around the web. Subscribe at dataelixir.com and follow us here for selections between issues. Covering machine learning, data visualization, analytics, and strategy.

743 followers829 following110 posts

Indexes speed up reads but slow writes. The real insight: indexes only help when you're returning <15-20% of rows. Beyond that, sequential scans win. Space and memory costs matter too. btree indexes often exceed table size.

dlt.github.ioIntroduction to PostgreSQL IndexesWho’s this for Basics How data is stored in disk How indexes speedup access to data Costs associated with indexes Disk Space Write operations Query planner Memory usage Types of Indexes Btree Hash…

What if a model’s prediction was literally an eigenvalue? This post kicks off a thoughtful series exploring spectrum-based models as a middle ground between linear models and neural nets, with interpretability and robustness baked in. A fun, slightly off-the-beaten-path ML read.

alexshtf.github.ioBehold the power of the spectrum!Eigenvalues as neurons: represent nonlinear models as the k-th eigenvalue of a learned symmetric matrix pencil. Explore monotonicity/convexity properties and train simple spectral models.

ClickHouse solved Advent of Code 2025 puzzles using single ClickHouse queries. No UDFs, no temp tables, no preprocessing. Just pure SQL doing things SQL probably shouldn't do. Impressive and slightly cursed in the best way.

clickhouse.comSolving the "Impossible" in ClickHouse: Advent of Code 2025At ClickHouse, we don't like the word "impossible." We believe that with the right tools, everything is a data problem. To prove it, we decided to complete the 2025 Advent of Code unconventionally:…

Your browser can run Python (Pyodide), execute OCR on PDFs, crop videos, and call LLM APIs—all without uploading anything to a server. The localStorage + CORS pattern makes surprisingly powerful tools possible with zero backend infrastructure.

simonwillison.netUseful patterns for building HTML toolsI’ve started using the term HTML tools to refer to HTML applications that I’ve been building which combine HTML, JavaScript, and CSS in a single file and use them to …

Haskell for data science? dataHaskell adds dataframes, NSE-style column operations, and compiler optimizations that turn chained operations into single-pass computations. Immutability + strong types + functional composition might be the combo we've been missing. jcarroll.com.au/2025/12/05/h...

jcarroll.com.auHaskell IS a Great Language for Data ScienceI’ve been learning Haskell for a few years now and I am really liking a lot of the features, not least the strong typing and functional approach. I thought it was lacking some of the things I missed…

Learning SQL is like learning a foreign language: you need to read more variations than you'll actually write. Learn disciplined canonical syntax for your own queries, but understand the messy dialects others use.

kb.databasedesignbook.comA modern guide to SQL JOINsThere are many SQL JOINs guides and tutorials, but this one takes a different approach. We try to avoid misleading wording and imagery, and we structure the material in a different way. The goal of…

Sometimes the best polars pattern is knowing when to exit the DataFrame. partitionby() splits data into a dict of frames, letting you process with list comprehensions. Cleaner than forcing everything through mapgroups() when further wrangling isn't needed.

emilyriederer.comPython Rgonomics: User-defined functions in polars | Emily RiedererPolars provides a consistent API for conducting transformations against a DataFrame. But what do you do when you need to apply a user-defined function beyond the native API? This post surveys the…

Data Elixir reposted

I curated some readings for class on "data tensions" and the list felt worth sharing. Come on a tour of datasets, books, the web, and AI with me... We'll start with this piece on the Google Books project: the hopes, dreams, disasters, and aftermath of building a public library on the internet. 1/n

theatlantic.comTorching the Modern-Day Library of Alexandria“Somewhere at Google there is a database containing 25 million books and nobody is allowed to read them.”

Debugging constraint problems is backwards: remove constraints until something works, then figure out what broke. No stack traces, just an "unsatisfiable." Forces you to think differently about what you're actually asking the system to solve. www.righto.com/2025/10/solv...

righto.comSolving the NYTimes Pips puzzle with a constraint solverThe New York Times recently introduced a new daily puzzle called Pips . You place a set of dominoes on a grid, satisfying various condition...

Data products shouldn't live forever by default. Netflix treats outdated metrics like deprecated software and actively sunset them. The cost of maintaining zombie datasets? Lost trust and accumulated technical debt that blocks innovation.

netflixtechblog.medium.comData as a Product: Applying a Product Mindset to Data at NetflixIntroduction: What if we treated data with the same care and intentionality as a consumer-facing product? Adopting a “data as a product”…

Data Elixir reposted

Replying to @dataelixir.com

What will you be using this #30DayMapChallenge? Cadence is offering its users £2,500 worth of prizes this #30daymapchallenge. And every user (new or existing) gets a free Professional upgrade for November! Learn more: cadence.cityscience.com/blog/30-day-...

cadence.cityscience.com30 Day Map ChallengeThe 30 Day Map Challenge with Cadence – November 2025  This November, Cadence is proud to support the 30 Day Map Challenge – a global celebration of maps, creativity and storytelling. Whether …

Stop fitting separate binomial models to compositional data! Your predictions that 130% of respondents chose option A reveal fundamental model misspecification. Dirichlet regression with Gaussian processes respects constraints.

ecogambler.netlify.appCompositional modeling of plant communities with Dirichlet regression | GAMblerCompositional data appears everywhere in scientific research, yet many analysts fall back on problematic approaches that ignore fundamental mathematical constraints. I demonstrate how Dirichlet…

Psychology's dirty secret: "data available upon request" usually means data not available at all. Researchers found systematic patterns in why data disappears over time. Open-washing is real and it's undermining reproducibility.

open.lnu.seLnuOpen | Meta-PsychologyMany journals now require data sharing and require articles to include a Data Availability Statement. However, several studies over the past two decades have shown that promissory notes about data…