Hi, Some time ago we noticed that there was a gap for atomically updating children. A child can be inserted using an api and updated using a different api. However there is currently no way to directly upsert (update or insert) a child. The same is true if you want to atomically upsert a list of children where some of them already exist in the parent but others haven't been inserted yet.
This behaviour seems inconsistent with atomic updates for parent items. Parents support atomic updates whether the document already exists in solr or not. To support the same feature in children, we created the following patch: https://issues.apache.org/jira/browse/SOLR-15213 The patch adds an extra atomic update type called merge, with either atomically updates the existing child or adds a new one if it doesn't exist. I am not sure what the process is for such a patch (or feature?) to make it into Solr's source code. Shall we just wait until somebody has time to review it, or do we need to submit it somewhere else? thanks, Endika Posadas
