# Merging old index to new index with new template

**URL:** <https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271>\
**Category:** Elasticsearch\
**Created:** [May 30, 2016, 5:29am UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271 "2016-05-30T05:29:06Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![gayathri](https://avatars.discourse-cdn.com/v4/letter/g/838e76/32.png) [@gayathri](https://discuss.elastic.co/u/gayathri)\
**Post date:** [May 30, 2016, 5:29am UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271/1 "2016-05-30T05:29:06Z")

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Please explain how to merge old index to new index with new template.

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**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [May 30, 2016, 6:07am UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271/2 "2016-05-30T06:07:26Z")

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You cannot, you need to reindex.

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**Author:** ![gayathri](https://avatars.discourse-cdn.com/v4/letter/g/838e76/32.png) [@gayathri](https://discuss.elastic.co/u/gayathri)\
**Post date:** [May 30, 2016, 6:31am UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271/3 "2016-05-30T06:31:48Z")

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Hi, Can you refer this link :[https://www.elastic.co/blog/changing-mapping-with-zero-downtime](https://www.elastic.co/blog/changing-mapping-with-zero-downtime)

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**Author:** ![gayathri](https://avatars.discourse-cdn.com/v4/letter/g/838e76/32.png) [@gayathri](https://discuss.elastic.co/u/gayathri)\
**Post date:** [May 30, 2016, 6:32am UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271/4 "2016-05-30T06:32:26Z")

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Could you please assist

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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, 10:48pm UTC](https://discuss.elastic.co/t/merging-old-index-to-new-index-with-new-template/51271/5 "2017-07-05T22:48:12Z")

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