My envision is if it could work in a similar way as projections work, it only fetches what is needed for indexing. If that's possible for you to implement I do not know. Yes I'm talking about the mass indexer and I want it to only fetch needed columns and collections when building the index to avoid unnecessary database calls.

I want to load the associations eagerly because of historical reasons, it is the way it has been done previously and it is hard to predict and test what consequences it will have to change the behaviour. So the current reason is to minimize risks.

Fetch plans for association indexing sounds interesting. If it would make it stop loading the associations it would work for me.

If I have missed to answer any of your questions, they were quite many and I think some of them touch the same subject, just tell me what more you want to know.

I think it can be good to know that this ticket arose from following question on Stackoverflow: http://stackoverflow.com/questions/28500459/can-hibernate-search-index-build-performance-be-improved-using-projection

I did not want to say in this ticket that projections should be used since there may be some other way to solve it.