Home GOTO Experts Roy van Rijn

Roy van Rijn is a director at OpenValue Rotterdam and a Java Champion. He worked on numerous projects all over the Netherlands as developer, architect and agile coach. He talks at conferences all around the world as well as local JUG events. You can read more at his blog or follow him on Twitter .

Upcoming conference sessions featuring Roy van Rijn

How Fast Can You Parse a File with 1 Billion Rows of Weather Data Using Java?

Last January a challenge was posted online by Gunnar Morling: How fast can you parse a file with one billion rows of weather data using Java?

Little did I know this deceivingly simple question would lead me down a path that taught me all about: parallelism, memory mapped files, SWAR techniques (SIMD as a register), bit twiddling, branchless code, mechanical sympathy, Graal native compilation and finally... I even turned to the dark side: using sun.misc.Unsafe.

Join me in this deep dive where I'll explain all the code changes and tricks that took me from the reference implementation which processes the billion records in >4 minutes, to processing everything in under two seconds.

Who knew Java could be this fast?

Thursday Oct 2 @ 15:15 @ GOTO Copenhagen 2025

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Content featuring Roy van Rijn

38:35
From Tic Tac Toe to AlphaGo: Playing games with AI
From Tic Tac Toe to AlphaGo: Playing games with AI
GOTO Amsterdam 2019
37:50
The Magic of Music Matching
The Magic of Music Matching
GOTO Oslo 2020
42:16
How Fast Can You Parse a File with 1 Billion Rows of Weather Data Using Java?
How Fast Can You Parse a File with 1 Billion Rows of Weather Data Using Java?
GOTO Amsterdam 2024
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