I probably should have pointed out the implications for disk I/O. In many cases, the serialization of the command in the journal has a smaller footprint on dis

I probably should have pointed out the implications for disk I/O. In many cases, the serialization of the command in the journal has a smaller footprint on disk than the data that's modified. Consider an extreme case where a small HTTP POST touches dozens or hundreds of records. And appending data to a log is essentially an ideal disk access pattern. Of course this can't be said for the snapshots, but you can offload that task to a replica server.