## MV_EXPAND

The `MV_EXPAND` command in ES|QL is a processing command that expands multivalued columns into one row per value, duplicating other columns. This command is particularly useful when dealing with data that contains multivalued fields and you want to create a separate row for each value in the multivalued field.

This functionality is currently in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.

### Syntax

`MV_EXPAND column`

#### Parameters

`column`
The multivalued column to expand.

### Examples

Here are some examples of how you can use the `MV_EXPAND` command in ES|QL:

1. Expanding a multivalued column 'a':

```esql
ROW a=[1,2,3], b="b"
| MV_EXPAND a
```

2. Expanding a multivalued column 'languages':

```esql
FROM employees
| MV_EXPAND languages
```

3. Expanding a multivalued column 'tags':

```esql
FROM blog_posts
| MV_EXPAND tags
```

In each of these examples, the `MV_EXPAND` command creates a new row for each value in the specified multivalued column.