Re: [hibernate-dev] Projecting an index

Current situation * Loading Wallposts directly from Lucene index. * Posts references properties that change relatively often or have cascading indexing impact if they would be saved within the Post document, e.g. User (photo, name, title, link), Classified (photo, title, decription), Group (photo, title, description), Comments (User, user.name, user.link) * Posts, Classifieds and Groups can be "Liked", which requires per user post processing because we want to show people liking stuff that are close to you * Of groups you can be a member or not so, it also requires post processing on a per user basis * In addition, some of these related objects have specific properties such as Event => eventDate, RSVP So, right now, we're optimizing this post processing process so that the impact is as low as possible. However, because all of these related objects are stored in different indexes it requires multiple hits against the index which has an impact on performance. Desired situation Since a lot of these related objects have common properties: photo, link, title, description and in this case of the Post display purposes we only need a small subset of the properties, it would be desirable to be able to query a single index in a one pass retrieval querying for (object type - id).

The idea of combining all these objects into a single index somehow feels wrong

and since I don't have any experience doing this, it's hard to oversee the impact of this, including potential bugs because this is not a common use case.

If I would be able to create a limited "combined secondary index" that would actually meet my use case. So, this brought me to my original question: can I project properties to a separate index. Which, given my new understanding of combining entities into a single index can also be read as: "Can I create two indexes based on a single entity, targeting only a subset of properties, basically duplicating index content”.