The best practice in updating an external data repository with Cypher data is by tagging every source (Cypher) object with a last modified date. For example, we maintain a repository of data from multiple systems/sources that allows us to perform analytics data across multiple system's data. Updates to the data repository with Cypher data based on a last modified data of the object pulled from the source enables an incremental refresh strategy.  Without a last modified date or equivalent, we are forced to do a full refresh every refresh cycle which is not ideal.