# Children aggregation **URL:** \ **Category:** Elasticsearch\ **Created:** [March 10, 2015, 12:22pm UTC](https://discuss.elastic.co/t/children-aggregation/22599 "2015-03-10T12:22:59Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![kazoompa\_2](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@kazoompa\_2](https://discuss.elastic.co/u/kazoompa_2)\ **Post date:** [March 10, 2015, 12:22pm UTC](https://discuss.elastic.co/t/children-aggregation/22599/1 "2015-03-10T12:22:59Z")
Hi, I was wondering whether this aggregation will work with parent documents residing in different indexes than the children documents? Are there any limitations with respect to shards? I remember parent-child relationships have shard limitation as stated here: [http://goo.gl/gU6Mcx](http://goo.gl/gU6Mcx). In short, I would like to know the limitations of this aggregation type since there were none described in the children agg documentation: [http://goo.gl/Y3yfhc](http://goo.gl/Y3yfhc). Thanks a lot. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![jpountz](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jpountz/32/45836_2.png) [@jpountz](https://discuss.elastic.co/u/jpountz)\ **Post date:** [March 14, 2015, 7:12am UTC](https://discuss.elastic.co/t/children-aggregation/22599/2 "2015-03-14T07:12:15Z")
Hi, This aggregation works with parent/child functionality which requires that parents and children are in the sane shard. So having parents and children in different indexes is not possible. See > **[Parent-Child Relationship | Elasticsearch: The Definitive Guide \[2.x\] | Elastic](https://www.elastic.co/guide/en/elasticsearch/guide/current/parent-child.html)** On Tue, Mar 10, 2015 at 5:22 AM, kazoompa [raminoacid@gmail.com](mailto:raminoacid@gmail.com) wrote: > Hi, > > I was wondering whether this aggregation will work with parent documents > residing in different indexes than the children documents? Are there any > limitations with respect to shards? I remember parent-child relationships > have shard limitation as stated here: [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://goo.gl/gU6Mcx). > > In short, I would like to know the limitations of this aggregation type > since there were none described in the children agg documentation: > [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://goo.gl/Y3yfhc). > > Thanks a lot. > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com) > [https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/055b8b28-d403-483e-92cb-a1b3ae04b252%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- Adrien Grand -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAL6Z4j4AhbQsVTk%2BuzdVy2W\_HK\_5qk9YaDROxzgcYx3\_fzv%3Dtw%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAL6Z4j4AhbQsVTk%2BuzdVy2W_HK_5qk9YaDROxzgcYx3_fzv%3Dtw%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 12:26am UTC](https://discuss.elastic.co/t/children-aggregation/22599/3 "2017-07-06T00:26:46Z")