About the performance I can't say too much but what I would recommend to do is that you loop over the results.
The first query gives you the number of groups (ngroups) q=*:*&groups=true&group.ngroups=true&group.field=myfield&start=0&rows=10000 And after that you execute the other queries in a simply change the start param q=*:*&groups=true&group.field=myfield&start=10000&rows=10000 q=*:*&groups=true&group.field=myfield&start=20000&rows=10000 q=*:*&groups=true&group.field=myfield&start=30000&rows=10000 and so on... I think like this you can avoid the solr out of memory exception. PS: But be carefull if you store all the rows on client side you need memory too :-) Bests Sandro -----Ursprüngliche Nachricht----- Von: Alok Bhandari [mailto:alokomprakashbhand...@gmail.com] Gesendet: Donnerstag, 3. Oktober 2013 13:02 An: solr-user@lucene.apache.org Betreff: Re: AW: Solr grouping performace Thanks for reply Sandro. My requirement is that I need all groups and then build compact data from it to send to server. I am not sure about how much RAM should be allocated to JVM instance to make it serve requests faster , any inputs on that are welcome. -- View this message in context: http://lucene.472066.n3.nabble.com/Solr-grouping-performace-tp4093300p4093311.html Sent from the Solr - User mailing list archive at Nabble.com.