Properties set to null are deleted in Neo4j but stay as explicit nulls in MongoDB and in Elasticsearch's _source. The API hides them, so this is only leftover data in storage.
- Fix it upstream: mongo-entity-manager should turn null values into $unset; elastic-entity-manager needs the equivalent.
- Optionally, add a one-off cleanup command for existing data.
Properties set to null are deleted in Neo4j but stay as explicit nulls in MongoDB and in Elasticsearch's _source. The API hides them, so this is only leftover data in storage.