I was also very surprised by this. I'm having a hard time accepting that I'd have to manually concat my columns to create sort keys and keep track of the corresponding queries for them, e.g. "BEGINS WITH..."? Granted, I only watched the video so maybe I'm missing something and that was just to simplify the presentation.
Yeah I'm with you, I've been reading up today about the GSIs in Dynamo but they really seem like a hack to get you a usable database, I need to come up with a good reason to use it at work, probably migrate some older databases so that we can multi-DC them.
