All the "auto-sharding" DBs have their own quirks, especially around hot key throughput. You often end up having to add "sharding bits" to the beginning of your

All the "auto-sharding" DBs have their own quirks, especially around hot key throughput. You often end up having to add "sharding bits" to the beginning of your keys to get enough throughput. The size of one partition is usually tiny compared to one partition of an RDBMS too. So it ends up being not nearly the panacea that it would seem to be.