databases

Same query. Same table. Same million rows. One day it takes 4 seconds . The next day, 4 milliseconds . Nothing changed in the data. The only thing that changed was one line — you added an index . Four seconds to four milliseconds is a thousand times faster, from one line of SQL. But here's the part nobody tells you: half the indexes people add do nothing. The query stays slow, the writes get slow…

Originally published at nlocoding.com 41% of enterprise database engineers already use AI tools daily to generate, optimize, or review SQL—up from just 14% in 2023 (Gartner, 2026). The new database arms race is invisible. Enterprises process 7.4x more data per person than they did five years ago. That’s not a typo. AI-assisted database development isn’t just about speed; it’s about not drowning i…

One PostgreSQL feature I recently revisited is earthdistance, a nice reminder that not every problem involving latitude and longitude requires a full GIS stack. The earthdistance extension provides a straightforward way to calculate great-circle distances between locations on Earth. Combined with PostgreSQL’s cube extension, ll_to_earth() converts latitude and longitude into a representation that…

So how do we handle such bugs? This is what we are going to try to answer in this article.

I’ve completed V1 of my Personal Expense Tracker , a small learning project built with Python and SQLite . This project was created primarily to learn by building rather than following a tutorial step by step. The goal of V1 was not to build a production-ready expense tracker. The goal was: Build the core application flow, understand the responsibilities of each layer, and make the fundamental fu…

Hannes Mühleisen and Mark Raasveldt started as AWS employees. The two built DuckDB, an analytical database that runs inside your process instead of on a server somebody has to administer. If you ship anything on top of DuckDB, your license does not change. Amazon did not buy the project. DuckDB, DuckLake, and Quack stay free and open source under MIT, and the nonprofit DuckDB Foundation continues…

A query joins a 2-billion-row fact table to a 40,000-row dimension table. The optimizer has to decide which side to broadcast and which side to hash. It reads the manifests and finds row counts, min and max values, and null counts for every column in every file. What it does not find is how many distinct customer IDs exist in the fact table. Without that number it guesses, and a wrong guess means…