When mongo came out the picked some bad defaults so it never waited for an ack for writes. So data was lost, but benchmarks looked amazing. It had a lot of othe

When mongo came out the picked some bad defaults so it never waited for an ack for writes. So data was lost, but benchmarks looked amazing. It had a lot of other problems, it became too big too fast by promising magic it didn't deliver. Not sure how it is right now. besides that flame attempt, his definition of columnar databases doesn't match the standard - Dynamodb is pretty much the complete opposite of columnar.