# What happens to existing segments when you reduce segment size?

**URL:** <https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805>\
**Category:** Elasticsearch\
**Created:** [September 29, 2016, 11:53am UTC](https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805 "2016-09-29T11:53:42Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jorgen](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@jorgen](https://discuss.elastic.co/u/jorgen)\
**Post date:** [September 29, 2016, 11:53am UTC](https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805/1 "2016-09-29T11:53:42Z")

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Will reducing segment size (by index.merge.policy.max\_merged\_segment) split existing segments towards the new max value? If not, is there any way to accomplish this?

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**Author:** ![mikemccand](https://avatars.discourse-cdn.com/v4/letter/m/f04885/32.png) [@mikemccand](https://discuss.elastic.co/u/mikemccand)\
**Post date:** [September 29, 2016, 1:23pm UTC](https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805/2 "2016-09-29T13:23:50Z")

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It won't.

But if those too-big segments accumulate \> 50% deletions then they are eligible for merging and could become smaller by being merged, depending on how much you lowered `index.merge_policy.max_merged_segment` by.

Mike McCandless

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**Author:** ![jorgen](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@jorgen](https://discuss.elastic.co/u/jorgen)\
**Post date:** [September 29, 2016, 1:28pm UTC](https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805/3 "2016-09-29T13:28:14Z")

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Thanks, just the info I needed.

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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 5, 2017, 10:16pm UTC](https://discuss.elastic.co/t/what-happens-to-existing-segments-when-you-reduce-segment-size/61805/4 "2017-07-05T22:16:07Z")

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