I'm not sure what you mean by "move to a new host" - all the built-in partitioning features are single-host for now, so this does not make much sense. There are

I'm not sure what you mean by "move to a new host" - all the built-in partitioning features are single-host for now, so this does not make much sense. There are plans to support remote (foreign) partitions, but that is in the future. A more immediate use case is partition-aware algorithms. For example joining equi-partitioned tables can be done at the partition level, and the smaller the partitions the faster the join (likely). Or partition-aware aggregation, when the partition key is included in the GROUP BY keys. And so on. In that case it makes sense to split the largest partitions to make them smaller.