# DocValues in ElasticSearch
**URL:** https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531
**Category:** Elasticsearch
**Created:** [September 18, 2015, 1:37am UTC](https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531 "2015-09-18T01:37:06Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@linlma](https://discuss.elastic.co/u/linlma)
#### Post date: [September 18, 2015, 1:37am UTC](https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531/1 "2015-09-18T01:37:06Z")
Hello ElasticSearch experts,
Wondering how DocValues implemented behind the scene which leveraging out of heap memory? Is it using Java nio ByteBuffer?
Any internal implementation documents or code are appreciated.
thanks in advance,
Lin
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### Author:  [@otisg](https://discuss.elastic.co/u/otisg)
#### Post date: [September 21, 2015, 7:30pm UTC](https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531/2 "2015-09-21T19:30:05Z")
Hi,
DocValues is a Lucene-level functionality. Here's the source:
[http://search-lucene.com/?q=lucene+DocValues&fc\_type=source+code](http://search-lucene.com/?q=lucene+DocValues&fc_type=source+code)
## Otis
Monitoring \* Alerting \* Anomaly Detection \* Centralized Log Management
Elasticsearch Consulting & Support \* [http://sematext.com/](http://sematext.com/)
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### Author:  [@linlma](https://discuss.elastic.co/u/linlma)
#### Post date: [September 21, 2015, 10:02pm UTC](https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531/3 "2015-09-21T22:02:11Z")
Thanks @otisg, I heard DocValue is leveraging memory out of JVM, is it implemented using java.nio.ByteBuffer? I read through the code and not found any details and your guidance is appreciated.
regards,
Lin
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 11:48pm UTC](https://discuss.elastic.co/t/docvalues-in-elasticsearch/29531/4 "2017-07-05T23:48:55Z")