# Clarification on how search\_type works

**URL:** <https://discuss.elastic.co/t/clarification-on-how-search-type-works/300203>\
**Category:** Elasticsearch\
**Created:** [March 21, 2022, 12:37pm UTC](https://discuss.elastic.co/t/clarification-on-how-search-type-works/300203 "2022-03-21T12:37:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ncoles](https://avatars.discourse-cdn.com/v4/letter/n/9e8a1a/32.png) [@ncoles](https://discuss.elastic.co/u/ncoles)\
**Post date:** [March 21, 2022, 12:37pm UTC](https://discuss.elastic.co/t/clarification-on-how-search-type-works/300203/1 "2022-03-21T12:37:40Z")

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I'm looking into some strange results from a "more like this" query involving search\_type.

I switched to `dfs_query_then_fetch` from the default query\_then\_fetch because I wanted more accurate results and the overhead didn't seem to make much difference.

However I'm finding the results with the standard `query_then_fetch` appear to be better, the ones that come back from `dfs_query_then_fetch` look less relevant (to the human eye anyway).

So I'm trying to understand the difference, have checked the documentation and it says

> Distributed term frequencies are calculated locally for each shard running the search.

I'm not sure what locally means in this sense, and what shard runs the search?

For context my more like this query runs against ten indices, some have \>10k documents, some much smaller with only 100 documents.

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**Author:** ![ncoles](https://avatars.discourse-cdn.com/v4/letter/n/9e8a1a/32.png) [@ncoles](https://discuss.elastic.co/u/ncoles)\
**Post date:** [April 9, 2022, 2:34pm UTC](https://discuss.elastic.co/t/clarification-on-how-search-type-works/300203/2 "2022-04-09T14:34:32Z")

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Is MLT not used by many people? I struggle to find people who understand it fully

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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:** [May 7, 2022, 2:35pm UTC](https://discuss.elastic.co/t/clarification-on-how-search-type-works/300203/3 "2022-05-07T14:35:32Z")

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