# Similarity class override

**URL:** <https://discuss.elastic.co/t/similarity-class-override/4028>\
**Category:** Elasticsearch\
**Created:** [March 3, 2011, 10:30pm UTC](https://discuss.elastic.co/t/similarity-class-override/4028 "2011-03-03T22:30:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Michael\_Korbakov](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/michael_korbakov/32/3199_2.png) [@Michael\_Korbakov](https://discuss.elastic.co/u/Michael_Korbakov)\
**Post date:** [March 3, 2011, 10:30pm UTC](https://discuss.elastic.co/t/similarity-class-override/4028/1 "2011-03-03T22:30:25Z")

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Hi everyone.

I'm looking for some way to plug in custom Similarity class into ES.  
I've found some mentions that it can be done quite easy, but no  
details. I need really simply override to set IDF=1 for all terms but  
there's no way to do it with standard ES settings.

Can anybody point me to some docs on it?

Thank you in advance.

-- Michael Korbakov

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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, 4:10am UTC](https://discuss.elastic.co/t/similarity-class-override/4028/2 "2017-07-06T04:10:54Z")

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