# I changed the elasticsearch.yml file, and added index.similairty.default.type: BM25, and rerun the elasticsearch executable file. Is it the right way to change similarity measure? My data are very big, I don't want to re index the data

**URL:** https://discuss.elastic.co/t/i-changed-the-elasticsearch-yml-file-and-added-index-similairty-default-type-bm25-and-rerun-the-elasticsearch-executable-file-is-it-the-right-way-to-change-similarity-measure-my-data-are-very-big-i-dont-want-to-re-index-the-data/2471
**Category:** Elasticsearch
**Created:** [June 11, 2015, 2:09pm UTC](https://discuss.elastic.co/t/i-changed-the-elasticsearch-yml-file-and-added-index-similairty-default-type-bm25-and-rerun-the-elasticsearch-executable-file-is-it-the-right-way-to-change-similarity-measure-my-data-are-very-big-i-dont-want-to-re-index-the-data/2471 "2015-06-11T14:09:26Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![harry747747](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/harry747747/32/483_2.png) [@harry747747](https://discuss.elastic.co/u/harry747747)
#### Post date: [June 11, 2015, 2:09pm UTC](https://discuss.elastic.co/t/i-changed-the-elasticsearch-yml-file-and-added-index-similairty-default-type-bm25-and-rerun-the-elasticsearch-executable-file-is-it-the-right-way-to-change-similarity-measure-my-data-are-very-big-i-dont-want-to-re-index-the-data/2471/1 "2015-06-11T14:09:26Z")

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I changed the elasticsearch.yml file, and added index.similairty.default.type: BM25, and rerun the elasticsearch executable file. Is it the right way to change similarity measure?  
My data are very big, I don't want to re index the data.

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### Author: ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 12:08am UTC](https://discuss.elastic.co/t/i-changed-the-elasticsearch-yml-file-and-added-index-similairty-default-type-bm25-and-rerun-the-elasticsearch-executable-file-is-it-the-right-way-to-change-similarity-measure-my-data-are-very-big-i-dont-want-to-re-index-the-data/2471/2 "2017-07-06T00:08:08Z")

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