# How to query a computed value from a document
**URL:** https://discuss.elastic.co/t/how-to-query-a-computed-value-from-a-document/97116
**Category:** Elasticsearch
**Created:** [August 15, 2017, 2:50pm UTC](https://discuss.elastic.co/t/how-to-query-a-computed-value-from-a-document/97116 "2017-08-15T14:50:05Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@ajay\_bh111](https://discuss.elastic.co/u/ajay_bh111)
#### Post date: [August 15, 2017, 2:50pm UTC](https://discuss.elastic.co/t/how-to-query-a-computed-value-from-a-document/97116/1 "2017-08-15T14:50:05Z")
Hi,
If I want to query a computed value from "a specific document" how this should be written for Kibana or Lucene or in painless script ?
For example, If I want to get delete\_time\_per\_ document = (indexing\_delete\_time\_in\_millis / indexing\_delete\_total) from the two fields in the same index mapping below
...
"indexing\_delete\_time\_in\_millis" : {
"type" : "long"
},
"indexing\_delete\_total" : {
"type" : "long"
},
....
Thanks
---
### Author:  [@abdon](https://discuss.elastic.co/u/abdon)
#### Post date: [August 18, 2017, 9:38am UTC](https://discuss.elastic.co/t/how-to-query-a-computed-value-from-a-document/97116/2 "2017-08-18T09:38:00Z")
Kibana has a concept of "scripted fields". These are fields that are calculated dynamically, and you can use them in visualizations just like any other fields. Check out the docs here: [https://www.elastic.co/guide/en/kibana/current/scripted-fields.html](https://www.elastic.co/guide/en/kibana/current/scripted-fields.html)
One thing you can't do though is query these scripted fields. If you want to do that, you will have to use a `script` query. For example, the following query will match all docs for which (indexing\_delete\_time\_in\_millis / indexing\_delete\_total) is larger than 1.0:
```
GET my_index/_search
{
"query": {
"script": {
"script": {
"inline": "doc['indexing_delete_time_in_millis'].value / doc['indexing_delete_total'].value > 1",
"lang": "painless"
}
}
}
}
```
Be careful with script queries though. They are computationally expensive and can result in errors (for example for document in which the indexing\_delete\_time\_in\_millis and indexing\_delete\_total do not exist, or for documents for which indexing\_delete\_total is 0.0).
A better way to solve this is to add the actual `delete_time_per_ document` field to your documents when you index those.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [September 15, 2017, 9:38am UTC](https://discuss.elastic.co/t/how-to-query-a-computed-value-from-a-document/97116/3 "2017-09-15T09:38:00Z")
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