# Is it possible to create a new index (transform) by using a field of array type from another index?

**URL:** <https://discuss.elastic.co/t/is-it-possible-to-create-a-new-index-transform-by-using-a-field-of-array-type-from-another-index/376607>\
**Category:** Elasticsearch\
**Created:** [April 1, 2025, 1:45am UTC](https://discuss.elastic.co/t/is-it-possible-to-create-a-new-index-transform-by-using-a-field-of-array-type-from-another-index/376607 "2025-04-01T01:45:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Nishanth\_Vimalesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nishanth_vimalesh/32/142363_2.png) [@Nishanth\_Vimalesh](https://discuss.elastic.co/u/Nishanth_Vimalesh)\
**Post date:** [April 1, 2025, 1:45am UTC](https://discuss.elastic.co/t/is-it-possible-to-create-a-new-index-transform-by-using-a-field-of-array-type-from-another-index/376607/1 "2025-04-01T01:45:08Z")

</div>

Hi Team,

I have a set of documents in an index (index\_a) with fields that look like this:

```auto
{
_id: <>,
another_id: <>,
float_field: <>,
array: [
{array_1_field_1: <>, array_1_field_2: <>},
{array_2_field_1: <>, array_2_field_2: <>}
]
}

```

I want to transform the documents in this index into a new index (index\_b) such that the elements in the array end up being separate documents:

```auto
{
_id: <new>,
another_id: <>,
float_field: <>,
field_1: <array_1_field_1>,
field_2: <array_1_field_2>
}

```

And another document:

```auto
{
_id: <new>,
another_id: <>,
float_field: <>,
field_1: <array_2_field_1>,
field_2: <array_2_field_2>
}

```

I would like this index\_b to be updated in real-time when documents in index\_a are added/updated/deleted. Would it be possible to do something like this?