presto-hive/src/main/java/io/prestosql/plugin/hive/HivePartitionKey.java/HivePartitionKey/getEstimatedSizeInBytes
class HivePartitionKey:    public int getEstimatedSizeInBytes()
    {
        return INSTANCE_SIZE + name.length() * Character.BYTES + value.length() * Character.BYTES;
    }