---
title: Data Stream fields
description: The data_stream fields take part in defining the new data stream naming scheme. In the new data stream naming scheme the value of the data stream fields...
url: https://www.elastic.co/elastic/docs-builder/docs/2322/reference/ecs/ecs-data_stream
---

# Data Stream fields
The data_stream fields take part in defining the new data stream naming scheme.
In the new data stream naming scheme the value of the data stream fields combine to the name of the actual data stream in the following manner: `{data_stream.type}-{data_stream.dataset}-{data_stream.namespace}`. This means the fields can only contain characters that are valid as part of names of data streams. More details about this can be found in this https://www.elastic.co/blog/an-introduction-to-the-elastic-data-stream-naming-scheme[blog post].
An Elasticsearch data stream consists of one or more backing indices, and a data stream name forms part of the backing indices names. Due to this convention, data streams must also follow index naming restrictions. For example, data stream names cannot include `\`, `/`, `*`, `?`, `"`, `<`, `>`, `|`, ` ` (space character), `,`, or `#`. Please see the Elasticsearch reference for additional restrictions: https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-create-index.html#indices-create-api-path-params.
<warning>
  These fields are in beta and are subject to change.
</warning>


## Data Stream field details


| Field                                                 | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | Level    |
|-------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|
| [data_stream.dataset](#field-data-stream-dataset)     | The field can contain anything that makes sense to signify the source of the data.Examples include `nginx.access`, `prometheus`, `endpoint` etc. For data streams that otherwise fit, but that do not have dataset set we use the value "generic" for the dataset value. `event.dataset` should have the same value as `data_stream.dataset`.Beyond the Elasticsearch data stream naming criteria noted above, the `dataset` value has additional restrictions:  * Must not contain `-`  * No longer than 100 characterstype: constant_keywordexample: `nginx.access`![OTel Badge](https://img.shields.io/badge/OpenTelemetry-4a5ca6?style=flat&logo=opentelemetry) [![not-applicable](https://img.shields.io/badge/n%2Fa-f2f4fb?style=flat)](/elastic/docs-builder/docs/2322/reference/ecs/ecs-opentelemetry#ecs-opentelemetry-relation) Not applicable. | extended |
| [data_stream.namespace](#field-data-stream-namespace) | A user defined namespace. Namespaces are useful to allow grouping of data.Many users already organize their indices this way, and the data stream naming scheme now provides this best practice as a default. Many users will populate this field with `default`. If no value is used, it falls back to `default`.Beyond the Elasticsearch index naming criteria noted above, `namespace` value has the additional restrictions:  * Must not contain `-`  * No longer than 100 characterstype: constant_keywordexample: `production`![OTel Badge](https://img.shields.io/badge/OpenTelemetry-4a5ca6?style=flat&logo=opentelemetry) [![not-applicable](https://img.shields.io/badge/n%2Fa-f2f4fb?style=flat)](/elastic/docs-builder/docs/2322/reference/ecs/ecs-opentelemetry#ecs-opentelemetry-relation) Not applicable.                                  | extended |
| [data_stream.type](#field-data-stream-type)           | An overarching type for the data stream.Currently allowed values are "logs" and "metrics". We expect to also add "traces" and "synthetics" in the near future.type: constant_keywordexample: `logs`![OTel Badge](https://img.shields.io/badge/OpenTelemetry-4a5ca6?style=flat&logo=opentelemetry) [![not-applicable](https://img.shields.io/badge/n%2Fa-f2f4fb?style=flat)](/elastic/docs-builder/docs/2322/reference/ecs/ecs-opentelemetry#ecs-opentelemetry-relation) Not applicable.                                                                                                                                                                                                                                                                                                                                                                   | extended |