# Cardinality aggregation: discrete shards

**URL:** <https://discuss.elastic.co/t/cardinality-aggregation-discrete-shards/29915>\
**Category:** Elasticsearch\
**Created:** [September 24, 2015, 12:44pm UTC](https://discuss.elastic.co/t/cardinality-aggregation-discrete-shards/29915 "2015-09-24T12:44:34Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![joris\_renkens](https://avatars.discourse-cdn.com/v4/letter/j/838e76/32.png) [@joris\_renkens](https://discuss.elastic.co/u/joris_renkens)\
**Post date:** [September 24, 2015, 12:44pm UTC](https://discuss.elastic.co/t/cardinality-aggregation-discrete-shards/29915/1 "2015-09-24T12:44:35Z")

</div>

Hi,

I want to do cardinality aggregation on userNr, which has very high cardinality (\> 1.000.000). Since my index has multiple shards and I'm routing based on userNr, the cardinality of the shards can simple be summed to the total cardinality. Is there a way to do this or should I write a custom aggregation?

Cheers,  
Joris

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 5, 2017, 11:48pm UTC](https://discuss.elastic.co/t/cardinality-aggregation-discrete-shards/29915/2 "2017-07-05T23:48:15Z")

</div>