# Boolean must\_not Query is having slow performance
**URL:** https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781
**Category:** Elasticsearch
**Created:** [November 2, 2016, 10:57pm UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781 "2016-11-02T22:57:22Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@lubp123](https://discuss.elastic.co/u/lubp123)
#### Post date: [November 2, 2016, 10:57pm UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781/1 "2016-11-02T22:57:22Z")
**Elasticsearch version** :
version : {
"number" : "2.4.1",
"build\_hash" : "c67dc32e24162035d18d6fe1e952c4cbcbe79d16",
"build\_timestamp" : "2016-09-27T18:57:55Z",
"build\_snapshot" : false,
"lucene\_version" : "5.5.2"
}
**Plugins installed** : []
**JVM version** : "1.8.0\_102"
**OS version** : OSX El Capitan 10.11.6
**Description of the problem including expected versus actual behavior** :
when we do a NOT based query on a large dataset of 300 million rows the time it takes to get data is very slow.
time taken: 12 minutes
number of rows: 300 million
returning roughly 80% of the data.
Index fields are all analyzed
```auto
curl -XGET 'http://localhost:9200/cars/item/_search?size=200' -d '
{ "profile": true, "query": { "bool": { "must_not": [{ "match": { "color": "red" } }, { "match": { "description": "car" } }] } }, "aggs": { "description": { "terms": { "field": "description", "size": 100 } } }} '
```
**Steps to reproduce** :
1. Do a simple curl command of a query in ES
2. Observe the time it takes from the profile information
---
### Author:  [@jpountz](https://discuss.elastic.co/u/jpountz)
#### Post date: [November 3, 2016, 10:12am UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781/2 "2016-11-03T10:12:44Z")
Phohibited clauses (MUST\_NOT) are indeed more costly than required clauses (MUST, FILTER) since the inverted index can barely help.
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### Author:  [@jpountz](https://discuss.elastic.co/u/jpountz)
#### Post date: [November 3, 2016, 10:13am UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781/3 "2016-11-03T10:13:47Z")
In your case, I suspect the time it takes to compute the response is mainly due to the amount of data: how long does it take to run a simple match\_all query?
---
### Author:  [@lubp123](https://discuss.elastic.co/u/lubp123)
#### Post date: [November 3, 2016, 8:51pm UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781/4 "2016-11-03T20:51:35Z")
hello Adrain
Thank you for your insight.
I did a Match All query on the data and it returns in 2.5 minutes. But this is still significantly less than the must\_not
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 10:06pm UTC](https://discuss.elastic.co/t/boolean-must-not-query-is-having-slow-performance/64781/5 "2017-07-05T22:06:47Z")