# Use of ElasticSearch Mapreduce
**URL:** https://discuss.elastic.co/t/use-of-elasticsearch-mapreduce/17221
**Category:** Elasticsearch
**Created:** [April 27, 2014, 12:25pm UTC](https://discuss.elastic.co/t/use-of-elasticsearch-mapreduce/17221 "2014-04-27T12:25:54Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Amaresh](https://discuss.elastic.co/u/Amaresh)
#### Post date: [April 27, 2014, 12:25pm UTC](https://discuss.elastic.co/t/use-of-elasticsearch-mapreduce/17221/1 "2014-04-27T12:25:54Z")
Hi Team,
I am a beginner in elasticsearch.I am able to do all bulk indexing using Java API.
ES is really good mechanism for searching purpose.But I am wondering why people talk about Mapreduce with ES.
Lets take the example I am trying:
I have a db column which contains 20000 records which contains duplicate datas.
I have put those records and indexed in ES and I want to get the matching records from elastic search.
Basic Doubt :After indexing in ES do I have to put the file in HDFS to run mapreduce program.If I have to put file HDFS and process then I what is the purpose of indexing here.
Hope I am clear enough to make others understand about my query.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 1:33am UTC](https://discuss.elastic.co/t/use-of-elasticsearch-mapreduce/17221/2 "2017-07-06T01:33:13Z")