# Fielddata cache and doc values
**URL:** https://discuss.elastic.co/t/fielddata-cache-and-doc-values/21370
**Category:** Elasticsearch
**Created:** [December 23, 2014, 3:17pm UTC](https://discuss.elastic.co/t/fielddata-cache-and-doc-values/21370 "2014-12-23T15:17:16Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Han\_JU](https://discuss.elastic.co/u/Han_JU)
#### Post date: [December 23, 2014, 3:17pm UTC](https://discuss.elastic.co/t/fielddata-cache-and-doc-values/21370/1 "2014-12-23T15:17:16Z")
Hi,
We are reviewing our ElasticSearch setup & settings, here's a question on
fielddata cache and usage of doc values.
Currently we set fielddata cache to be 30% of the heap size and we've
enabled doc\_values for all fields that we want to sort or aggregate (except
2 boolean fields).
As I understand, doc values are a form of on disk cache of field data. So
my questions is, by using doc values, can we reduce the memory fielddata
cache size? Say to 10%, is it a good idea?
Thanks!
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### Author:  [@vineeth\_mohan\_2](https://discuss.elastic.co/u/vineeth_mohan_2)
#### Post date: [December 23, 2014, 3:29pm UTC](https://discuss.elastic.co/t/fielddata-cache-and-doc-values/21370/2 "2014-12-23T15:29:24Z")
Hi ,
Yes , definitely doc values would be a better idea.
As it is not 100% memory resident , it will give a lot better stability and
memory optimization to the system.
On the flip side, performance might go down to , say 10 to 15%.
Thanks
Vineeth
On Tue, Dec 23, 2014 at 8:47 PM, Han JU [ju.han.felix@gmail.com](mailto:ju.han.felix@gmail.com) wrote:
> Hi,
>
> We are reviewing our Elasticsearch setup & settings, here's a question on
> fielddata cache and usage of doc values.
>
> Currently we set fielddata cache to be 30% of the heap size and we've
> enabled doc\_values for all fields that we want to sort or aggregate (except
> 2 boolean fields).
> As I understand, doc values are a form of on disk cache of field data. So
> my questions is, by using doc values, can we reduce the memory fielddata
> cache size? Say to 10%, is it a good idea?
>
> Thanks!
>
> --
> You received this message because you are subscribed to the Google Groups
> "elasticsearch" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com).
> To view this discussion on the web visit
> [https://groups.google.com/d/msgid/elasticsearch/914962d7-66ca-467e-bd35-fe520317dda9%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/914962d7-66ca-467e-bd35-fe520317dda9%40googlegroups.com)
> [https://groups.google.com/d/msgid/elasticsearch/914962d7-66ca-467e-bd35-fe520317dda9%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/914962d7-66ca-467e-bd35-fe520317dda9%40googlegroups.com?utm_medium=email&utm_source=footer)
> .
> For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 12:42am UTC](https://discuss.elastic.co/t/fielddata-cache-and-doc-values/21370/3 "2017-07-06T00:42:11Z")