[chrisjc]

> So suddenly writing 3 million objects that begin with a t would cause an uneven load or hotspot on the backing shards.

makes sense

> The system realizes your new access pattern and determines new prefixes and moves data around to accommodate what it thinks your needs are.

What does "determines new prefixes" mean? Obviously AWS isn't going to come up with new prefixes and change object names.

So does AWS maintain prefix-surrogates (prefix sub-string(0,?) references) and those are what actually gets shuffled around to handle the new unbalanced workload? Sort of like resharding?

Moreover, since it's really prefix-surrogates being used, the recommendation of randomizing prefixes can be replace with randomizing prefix-surrogates and delegated to AWS, removing the prior responsibility from the customer. Hence the 2018 announcement https://aws.amazon.com/about-aws/whats-new/2018/07/amazon-s3...