Just a few days after finishing Advent of Code 2023, I got nerd sniped1 by Gunnar Morling with his One Billion Rows Challenge. The challenge is to compute the average, min and max temperature value over 1 billion data points keyed by city name. As fast as possible, using only the Java standard library. I conveniently ignored the Java constraint and did a 1BRC implementation in C instead. It's written in standard C11 and uses POSIX threads for processing the file in parallel. Naive implementat...
