The question as I read it was composite documents, not cross-collection joins.
If the joined core is small enough to be replicated across all replicas of your main collection, then cross-core joining works well, as it is all within one instance. As to composite documents, I have sometimes wondered whether a SearchComponent (such as the ExpandComponent) or a DocTransformer could facilitate this. Once the 10 documents that are to be returned to the user have been suggested, retro-fitting the joined documents to them shouldn't be a huge amount of work, performance-wise. What it'd take, though, is a reasonable amount of thinking to get said components right. Upayavira On Mon, Aug 17, 2015, at 05:19 PM, Erick Erickson wrote: > True, I haven't looked at it closely. Not sure where it is in the > priority list though. > > However, I would recommend you _really_ look at _why_ you > think you need cross-collection joins. Likely they will be expensive, > and whether they're performant in your situation will be a question. > > If at all possible, Solr is much happier/more flexible if you can > denormalize your data and live with the fact that your index > will be bigger. > > Best, > Erick > > On Sun, Aug 16, 2015 at 12:59 PM, naga sharathrayapati > <sharathrayap...@gmail.com> wrote: > > https://issues.apache.org/jira/browse/SOLR-7090 > > > > I see this jira open in support of joins which might solve the problem. > > > > On Sun, Aug 16, 2015 at 2:51 PM, Erick Erickson <erickerick...@gmail.com> > > wrote: > > > >> bq: Is there any chance of this feature(merge the results to create a > >> composite > >> document) coming out in the next release 5.3 > >> > >> In a word "no". And there aren't really any long-range plans either that > >> I'm > >> aware of. > >> > >> You could also explore streaming aggregation, if the need here is more > >> batch-oriented. > >> > >> If at all possible, Solr is much more flexible if you can de-normlize your > >> data > >> rather than try to make Solr work like an RDBMS. Of course it goes against > >> the training of all DB Admins, but it's often the best option. > >> > >> So have you explored denormalizing and do you know it's not a viable > >> option? > >> > >> Best, > >> Erick > >> > >> On Sun, Aug 16, 2015 at 12:45 PM, naga sharathrayapati > >> <sharathrayap...@gmail.com> wrote: > >> > Is there any chance of this feature(merge the results to create a > >> composite > >> > document) coming out in the next release 5.3 ? > >> > > >> > On Sun, Aug 16, 2015 at 2:08 PM, Upayavira <u...@odoko.co.uk> wrote: > >> > > >> >> You can do what are called "pseudo joins", which are eqivalent to a > >> >> nested query in SQL. You get back data from one core, based upon > >> >> criteria in the other. You cannot (yet) merge the results to create a > >> >> composite document. > >> >> > >> >> Upayavira > >> >> > >> >> On Sun, Aug 16, 2015, at 06:02 PM, Nagasharath wrote: > >> >> > I exactly have the same requirement > >> >> > > >> >> > > >> >> > > >> >> > > On 13-Aug-2015, at 2:12 pm, Kiran Sai Veerubhotla < > >> sai.sq...@gmail.com> > >> >> wrote: > >> >> > > > >> >> > > does solr support joins? > >> >> > > > >> >> > > we have a use case where two collections have to be joined and the > >> >> join has > >> >> > > to be on the faceted results of the two collections. is this > >> possible? > >> >> > >>