# Change in dense\_vector field indexation default in ES 8.14 - Existing indices behaviour?

**URL:** <https://discuss.elastic.co/t/change-in-dense-vector-field-indexation-default-in-es-8-14-existing-indices-behaviour/362385>\
**Category:** Elasticsearch\
**Tags:** vector-search\
**Created:** [July 2, 2024, 1:52pm UTC](https://discuss.elastic.co/t/change-in-dense-vector-field-indexation-default-in-es-8-14-existing-indices-behaviour/362385 "2024-07-02T13:52:07Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![clemsau](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/clemsau/32/135714_2.png) [@clemsau](https://discuss.elastic.co/u/clemsau)\
**Post date:** [July 2, 2024, 1:52pm UTC](https://discuss.elastic.co/t/change-in-dense-vector-field-indexation-default-in-es-8-14-existing-indices-behaviour/362385/1 "2024-07-02T13:52:07Z")

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Hello,

In the [ES 8.14 patch notes,](https://www.elastic.co/guide/en/elasticsearch/reference/current/release-notes-8.14.0.html) we can see that now, the `dense_vector` field type used for vector search will now be indexed by default with the quantized `hnsw_int8` graphs.

Prior to that, `hnsw_int8` was the graph used to index the field, only optionally. The default was plain `hnsw`.

On the upgrade of our cluster (from version 8.10, to version 8.14), we didn't observe any downtime nor any behavior change. We expect the existing indices to have their `dense_vector` fields still indexed as `hnsw` as it was the default at the time of the index creation & field mapping.

Will the future documents added to the index created in 8.10 have their `dense_vector` fields indexed as `hnsw`, like the previous documents ?

Would adding to the mapping a new `dense_vector` field to this old index now default to `hnsw_int8` ?

Do I need to create a new index to observe the new behavior of `hnsw_int8` being the default and `hnsw` being used only optionally ?

I couldn't find anything in the documentation covering how upgrading the clusters would impact or not the existing indices. But if there is some that would answer my confusions, please redirect me to it.

Regards,

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<div class="post-metadata">

**Author:** ![Carlos\_D](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/carlos_d/32/126245_2.png) [@Carlos\_D](https://discuss.elastic.co/u/Carlos_D)\
**Post date:** [July 2, 2024, 4:13pm UTC](https://discuss.elastic.co/t/change-in-dense-vector-field-indexation-default-in-es-8-14-existing-indices-behaviour/362385/2 "2024-07-02T16:13:04Z")

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Hi @clemsau !

The defaults for `dense_vector` fields depend on the Elasticsearch version that the index was created on.

That means that an index created prior to 8.14 will maintain `hnsw` as the default. An index that was created on 8.14 or afterwards, will use `hnsw_int8` as the default.

So, adding a new `dense_vector` field to a pre-8.14 index should have the same defaults as before.

Hopefully that helps!