Databaseline is a blog about data, technology, software engineering and architecture, leadership, the music industry, diversity, and stereoscopy by Ian Hellström (he/him/his).

Ian (a.k.a. Christian) Hellström has been a data and machine learning engineer at various companies, including D2iQ, Spotify, Bosch and Sievo. He currently resides in Hamburg, Germany.

On oracle.rtfd.io, Ian has launched an initiative for developers to learn more about SQL and PL/SQL optimization techniques for Oracle Database, which attracts approximately 10,000 unique visitors each month. It contains more than a hundred pages of high-quality material—for free!

He is the originator of The (Unfortunately Realistic) Rules of Data Quality™:

  1. Assume nothing.
  2. Trust no one.
  3. If no one looks at or uses the data, it’s always rubbish.
  4. Documentation is either unavailable or almost certainly wrong.

In short, when it comes to data, don’t automatically believe everything you see, read, or hear about it.

Please note that all opinions expressed here or elsewhere are those of the author and they do not necessarily represent the sentiments or opinions of any employer, client, or colleague.

Peer-Reviewed Articles

Original research papers Ian Hellström has been involved in are listed in reverse chronological order:

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