# Count distinct values lower than doc\_count

**URL:** <https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840>\
**Category:** Elasticsearch\
**Created:** [August 24, 2018, 6:05am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840 "2018-08-24T06:05:24Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![Dilip\_Kumar](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dilip_kumar/32/15459_2.png) [@Dilip\_Kumar](https://discuss.elastic.co/u/Dilip_Kumar)\
**Post date:** [August 24, 2018, 6:05am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/1 "2018-08-24T06:05:24Z")

</div>

Hi  
i am using cardinality Aggregation Query but some time unique count value less than the previous value..

"size": 0,  
"aggs": {  
"camgroup": {  
"filter": {  
"term": {  
"RTT": "184"  
}  
},  
"aggs": {  
"campevents": {  
"terms": {  
"field": "REE",  
"size": 100000  
},  
"aggs": {  
"zingids": {  
"cardinality": {  
"field": "ZID"  
}  
}  
}  
}  
}  
}  
}  
output =\>  
{  
"key" : "9",  
"doc\_count" : 20224,  
"zingids" : {  
"value" : 20099  
}  
},  
{  
"key" : "5",  
"doc\_count" : 12439,  
"zingids" : {  
"value" : 12299  
}  
},

My question is why doc\_count is difference than value, and some time value(12299) becomes less than previous value..

---

<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [August 24, 2018, 6:44am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/2 "2018-08-24T06:44:16Z")

</div>

In order to scale, certain types of aggregations are approximate, and [this includes the cardinality aggregation](https://www.elastic.co/guide/en/elasticsearch/reference/6.4/search-aggregations-metrics-cardinality-aggregation.html#_counts_are_approximate). You can tune the accuracy, but not get it absolutely accurate if your cardinality is quite high.

---

<div class="post-metadata">

**Author:** ![Dilip\_Kumar](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dilip_kumar/32/15459_2.png) [@Dilip\_Kumar](https://discuss.elastic.co/u/Dilip_Kumar)\
**Post date:** [August 24, 2018, 6:45am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/3 "2018-08-24T06:45:36Z")

</div>

Please suggest how can i get accurate value..doc\_count is also not accurate?

---

<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [August 24, 2018, 6:52am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/4 "2018-08-24T06:52:51Z")

</div>

Document counts are accurate. The approximation only applies to a subset off aggregation types, and it is generally noted in the docs where values are likely to be approximate.

---

<div class="post-metadata">

**Author:** ![Dilip\_Kumar](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dilip_kumar/32/15459_2.png) [@Dilip\_Kumar](https://discuss.elastic.co/u/Dilip_Kumar)\
**Post date:** [August 24, 2018, 6:57am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/5 "2018-08-24T06:57:35Z")

</div>

Thank you for reply, i should use doc\_count rather than value from out put

{  
"key" : "4",  
"doc\_count" : 49376,  
"zingids" : {  
"value" : 49066  
}  
},  
{  
"key" : "9",  
"doc\_count" : 21149,  
"zingids" : {  
"value" : 21462  
}  
},

is this will be helpful =\>  
"precision\_threshold": 100

---

<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [August 24, 2018, 6:59am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/6 "2018-08-24T06:59:48Z")

</div>

You can increase precision by increasing the `precision_threshold` and it takes a value up to 40000.

---

<div class="post-metadata">

**Author:** ![Dilip\_Kumar](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dilip_kumar/32/15459_2.png) [@Dilip\_Kumar](https://discuss.elastic.co/u/Dilip_Kumar)\
**Post date:** [August 24, 2018, 7:06am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/7 "2018-08-24T07:06:42Z")

</div>

what does it mean? `precision_threshold` and it takes a value up to 40000.

---

<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [August 24, 2018, 7:07am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/8 "2018-08-24T07:07:42Z")

</div>

The maximum value that you can set is 40000. This increases precision but uses more system resources.

---

<div class="post-metadata">

**Author:** ![Dilip\_Kumar](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dilip_kumar/32/15459_2.png) [@Dilip\_Kumar](https://discuss.elastic.co/u/Dilip_Kumar)\
**Post date:** [August 24, 2018, 7:11am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/9 "2018-08-24T07:11:20Z")

</div>

I can also update my query, because i need count so no need to sub aggs :slightly\_smiling\_face  
"size": 0,  
"aggs": {  
"camgroup": {  
"filter": {  
"term": {  
"RT": "184"  
}  
},  
"aggs": {  
"campevents": {  
"terms": {  
"field": "REE",  
"size": 1000000  
}  
}  
}  
}  
}  
this will count accurate value..

---

<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:** [September 21, 2018, 7:11am UTC](https://discuss.elastic.co/t/count-distinct-values-lower-than-doc-count/145840/10 "2018-09-21T07:11:22Z")

</div>

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