# Rolling index with parent/child?
**URL:** https://discuss.elastic.co/t/rolling-index-with-parent-child/49237
**Category:** Elasticsearch
**Created:** [May 4, 2016, 10:51pm UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237 "2016-05-04T22:51:47Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@kucera.jan.cz](https://discuss.elastic.co/u/kucera.jan.cz)
#### Post date: [May 4, 2016, 10:51pm UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/1 "2016-05-04T22:51:47Z")
Hello everyone,
I was wondering whether there is a possibility to have rolling index (time based) with parent/child relationship.
I am indexing time based data (index per day, all aliased) and all docs are related to one parent with ID. Users than can in any time label each parent and I would need to search (and aggregate) all child docs with certain labels.
Is there any other possibility than [Application-side joins](https://www.elastic.co/guide/en/elasticsearch/guide/current/application-joins.html) ?
Thanks in advance
Jan
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### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [May 4, 2016, 11:03pm UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/2 "2016-05-04T23:03:12Z")
You can do this, children can refer to a non-existent parent.
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### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [May 5, 2016, 5:28am UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/3 "2016-05-05T05:28:45Z")
Parent/child is as you point out very difficult to use with time-based indices due to the limitations that the parent need to be in the same shard as the children, thereby requiring a parent per time-based index in order for filtering on parent fields to work. Depending on the number of children per parent and the frequency at which parent tags change, denormalisation and/or application side joins are generally the best way to go.
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### Author:  [@kucera.jan.cz](https://discuss.elastic.co/u/kucera.jan.cz)
#### Post date: [May 5, 2016, 5:46am UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/4 "2016-05-05T05:46:56Z")
Hello @Christian_Dahlqvist,
thank you for your answer. The frequency of parent tagging can be hundreds per minute. However I need to apply that tag for ALL docs in the cluster that are related to the parent.
If I understand correctly:
2016-01-01 - I create child C1 with relation to A
2016-01-02 - I create child C2 with relation to A
If user will tag parent A system needs to create/update parent document in both 2016-01-01 and 2016-01-02 indices, is that correct?
Also if next day someone will create new index (2016-01-03) I would be forced to insert parent doc A to this index too...?
Jan
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### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [May 5, 2016, 7:00am UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/5 "2016-05-05T07:00:39Z")
If the update frequency is that high I suspect application-side join is the best approach.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 10:53pm UTC](https://discuss.elastic.co/t/rolling-index-with-parent-child/49237/6 "2017-07-05T22:53:51Z")