Pass a certain point, you ought to think about whether to keep using a RDBMS as a K-V store or switch to a real distributed K-V store like Cassandra, ScyllaDB,

Pass a certain point, you ought to think about whether to keep using a RDBMS as a K-V store or switch to a real distributed K-V store like Cassandra, ScyllaDB, DynamoDB and the like About hot spots, it has always been an issue with K-V stores, and the only real solution is a good key design, though there are some tricks: * Use a uniformly distributed but deterministic key prefix. For example, instead of using raw user_id as key, attach a small hash before it: (hash(<user_id>), <user_id>) This can help with load distribution if your <user_id> is not uniformly distributed by itself such as a phone or id number. * Add more data to your key to increase cardinality. For example, with time series data, instead of using object_id as partition key, use (user_id, time_bucket) so the data for a busy object will get split into different partition over time.