# How to get exact unique doc count based on some fields

**URL:** <https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718>\
**Category:** Elasticsearch\
**Created:** [July 17, 2020, 7:51pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718 "2020-07-17T19:51:24Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![sandeep\_rana](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@sandeep\_rana](https://discuss.elastic.co/u/sandeep_rana)\
**Post date:** [July 17, 2020, 7:51pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/1 "2020-07-17T19:51:24Z")

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Any way to find exact unique document count ..

based on some fields..

I have also tried cardinality its not working as expected

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**Author:** ![elasticforme](https://avatars.discourse-cdn.com/v4/letter/e/f05b48/32.png) [@elasticforme](https://discuss.elastic.co/u/elasticforme)\
**Post date:** [July 17, 2020, 9:38pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/2 "2020-07-17T21:38:09Z")

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I use sql, for example

select username from index\_name group by username

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<div class="post-metadata">

**Author:** ![sandeep\_rana](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@sandeep\_rana](https://discuss.elastic.co/u/sandeep_rana)\
**Post date:** [July 19, 2020, 1:21pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/3 "2020-07-19T13:21:01Z")

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Thank you Sachin ,  
How we can do in elasticsearch .. ???

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<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:** [July 19, 2020, 1:32pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/4 "2020-07-19T13:32:38Z")

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How much data are you querying? What is the expected cardinality you are measuring? What is the use case?

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<div class="post-metadata">

**Author:** ![sandeep\_rana](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@sandeep\_rana](https://discuss.elastic.co/u/sandeep_rana)\
**Post date:** [July 19, 2020, 1:42pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/5 "2020-07-19T13:42:41Z")

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Hi ,

I have 100K documents on one index pattern like `(localhost_com_1005_do_br_scs_618229232191937012_8662_*)`. There is one field called id , so just need unique document count based on id.keyword.

Because may be chances to get duplicate while querying with index pattern ..

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<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:** [July 19, 2020, 2:05pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/6 "2020-07-19T14:05:35Z")

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How many of indices and shards does that correspond to? What is the total size on disk?

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<div class="post-metadata">

**Author:** ![sandeep\_rana](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@sandeep\_rana](https://discuss.elastic.co/u/sandeep_rana)\
**Post date:** [July 20, 2020, 4:48am UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/7 "2020-07-20T04:48:23Z")

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There is only one shard no replica . 200GB is disk size.

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<div class="post-metadata">

**Author:** ![elasticforme](https://avatars.discourse-cdn.com/v4/letter/e/f05b48/32.png) [@elasticforme](https://discuss.elastic.co/u/elasticforme)\
**Post date:** [July 21, 2020, 5:38pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/8 "2020-07-21T17:38:53Z")

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> [@sandeep\_rana](#):
>
> may be chances to get duplicate while quer

I go to kibana - dev tool

```
GET _sql?format=txt
{
  "query": """
        select count(*), id
    from "localhost_com_1005_do_br_scs_618229232191937012_8662_*" 
        group by id
        """
}   

```

Problem you might face is that id is also a elasticsearch field.

use following to see what exactly field name listed in elasticsearch

GET _sql?format=txt  
{  
"query": """  
desc "localhost\_com\_1005\_do\_br\_scs\_618229232191937012\_8662_\*"  
"""  
}

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<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:** [August 18, 2020, 5:38pm UTC](https://discuss.elastic.co/t/how-to-get-exact-unique-doc-count-based-on-some-fields/241718/9 "2020-08-18T17:38:57Z")

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