Data of the real world are permanently changing. What has been there yesterday may no longer be valid today. I discovered the situation shown above of a 30 km/h speed indication in a small German city some day on my way to work. The digit “3” wore out because it was right under the track of the left wheels of a typical vehicle whereas the “0” was in the middle of the lane and, thus, hardly touched by the tires.
I’m glad I took the picture that day because just a few days later, the “3” got repainted by the municipality.
But how do you want to keep track of these “oddities” in your data lake? This is just one of the aspects why we have started this blog.