# Can I use the Exact Knn function when using Hybrid Search (using rrf)?

**URL:** <https://discuss.elastic.co/t/can-i-use-the-exact-knn-function-when-using-hybrid-search-using-rrf/360302>\
**Category:** Elastic Search\
**Created:** [May 27, 2024, 1:54pm UTC](https://discuss.elastic.co/t/can-i-use-the-exact-knn-function-when-using-hybrid-search-using-rrf/360302 "2024-05-27T13:54:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bbasosuho](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/bbasosuho/32/123999_2.png) [@bbasosuho](https://discuss.elastic.co/u/bbasosuho)\
**Post date:** [May 27, 2024, 1:54pm UTC](https://discuss.elastic.co/t/can-i-use-the-exact-knn-function-when-using-hybrid-search-using-rrf/360302/1 "2024-05-27T13:54:06Z")

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Hi  
I am currently using Exact knn for Vector Search.  
Can I use the Exact Knn function when using Hybrid Search (using rrf)?  
When I enter script\_score into the query in Hybrid Search, it does not run.  
I wonder if Exact Knn is possible in Hybrid Search.  
Thanks

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**Author:** ![joemcelroy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/joemcelroy/32/103757_2.png) [@joemcelroy](https://discuss.elastic.co/u/joemcelroy)\
**Post date:** [May 28, 2024, 9:12am UTC](https://discuss.elastic.co/t/can-i-use-the-exact-knn-function-when-using-hybrid-search-using-rrf/360302/2 "2024-05-28T09:12:37Z")

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Hey,

Which version of Elasticsearch are you using?

One possibility is using sub\_searches: one script score query and another BM25 based query. [Semantic search | Elasticsearch Guide [8.13] | Elastic](https://www.elastic.co/guide/en/elasticsearch/reference/current/semantic-search.html#semantic-search-hybrid-search)

This will be replaced with retrievers in 8.14, released in the next couple of weeks.

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [June 25, 2024, 9:13am UTC](https://discuss.elastic.co/t/can-i-use-the-exact-knn-function-when-using-hybrid-search-using-rrf/360302/3 "2024-06-25T09:13:11Z")

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