Nah this will totally be an issue. You can be on the extreme end of replication or the extreme end of sharding and experience performance problems. Sharding is

Nah this will totally be an issue. You can be on the extreme end of replication or the extreme end of sharding and experience performance problems. Sharding is more likely to hotspot depending on where hot data is consistent. The solution in most cases is a simple database that acts as a pointer database user db -> user's db. That is generated on the creation of a user. From here you create some simple cold storage models ( if user isn't active ) and some warm models which will scale out the db if the user's db grows it shards and replicates for more read access. But the last thing you want is to slow replication or have one DB that can't move to balance resource utilization. There are some new DB tech that does this without even sweating the deets.