# Number of Segments

**URL:** <https://discuss.elastic.co/t/number-of-segments/60393>\
**Category:** Elasticsearch\
**Created:** [September 13, 2016, 2:58pm UTC](https://discuss.elastic.co/t/number-of-segments/60393 "2016-09-13T14:58:05Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![nik9000](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nik9000/32/44947_2.png) [@nik9000](https://discuss.elastic.co/u/nik9000)\
**Post date:** [September 13, 2016, 3:18pm UTC](https://discuss.elastic.co/t/number-of-segments/60393/2 "2016-09-13T15:18:51Z")

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> [@mhughes](#):
>
> what are the benefits of merging? reduced memory? less file handles? improved search speed? all of the above?

Pretty much all of the above

> [@mhughes](#):
>
> how much better are the benefits of merging to 1 vs merging to 2?

It is hard to say. I mean, it is half the number of segments but an index that gets written to constantly is going to have dozens of segments and that performs just fine for most things.

> [@mhughes](#):
>
> is it faster to merge to 1 than 2?

Slower, I think.

> [@mhughes](#):
>
> what should you merge down to? 1 segment? 2? it depends? If "it depends", depends on what? index size?

I'd do one, but only after I'm super sure I'll never write to the index again. I don't expect you'll see a huge difference between one shard and two but it might be worth testing if you are particularly concerned about performance.

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