# Creating a namespace
<a name="s3-tables-namespace-create"></a>

A table namespace is a logical construct that you group tables under within an Amazon S3 table bucket. Each table belongs to a single namespace. Before creating a table in a table bucket, you must create a namespace to group tables under. You can create a namespace by using the Amazon S3 console, AWS Command Line Interface (AWS CLI), Amazon S3 REST API, AWS SDKs, or integrated query engines.

**Namespace names**

The following naming rules apply to namespaces:
+ Names must be between 1 and 255 characters long.
+ Names can consist only of lowercase letters, numbers, and underscores (`_`). Underscores aren't allowed at the start or end of namespace names.
+ Names must begin and end with a letter or number.
+ Names must not contain hyphens (`-`) or periods (`.`).
+ A namespace must be unique within a table bucket.
+ Namespace names must not start with the reserved prefix `aws`.

For more information about valid namespace names, see [Naming rules for tables and namespaces](s3-tables-buckets-naming.md#naming-rules-table).

## Using the S3 console and Amazon Athena
<a name="create-namespace-console"></a>

The following procedure uses the **Create table with Athena** workflow to create a namespace in the Amazon S3 console. If you don't want to also use Amazon Athena to create a table in your namespace, you can cancel the workflow after creating your namespace. 

**To create a namespace**

1. Sign in to the AWS Management Console and open the Amazon S3 console at [https://console.aws.amazon.com/s3/](https://console.aws.amazon.com/s3/).

1. In the left navigation pane, choose **Table buckets**.

1. On the **Table buckets** page, choose the bucket that you want to create a namespace in.

1. On the bucket details page, choose **Create table with Athena**. 

1. In the **Create table with Athena** dialog box, choose **Create a namespace**, and then choose **Create namespace**.

1. Enter a name in the **Namespace name** field. Namespace names must be 1 to 255 characters and unique within the table bucket. Valid characters are a–z, 0–9, and underscores (`_`). Underscores aren't allowed at the start or end of namespace names.

1. Choose **Create namespace**.

1. If you also want to create a table, choose **Create table with Athena**. For more information about creating a table with Athena, see [Using the S3 console and Amazon Athena](s3-tables-create.md#create-table-console). If you don't want to create a table right now, choose **Cancel**.

## Using the AWS CLI
<a name="create-table-namespace-CLI"></a>

This example shows how to create a table namespace by using the AWS CLI. To use this example, replace the `user input placeholders` with your own information.

```
aws s3tables create-namespace \
    --table-bucket-arn arn:aws:s3tables:us-east-1:111122223333:bucket/amzn-s3-demo-bucket1 \ 
    --namespace example_namespace
```

## Using a query engine
<a name="create-table-namespace-engine"></a>

You can create a namespace in an Apache Spark session connected to your Amazon S3 table buckets.

This example shows you how to create a table by using `CREATE` statements in a query engine integrated with S3 Tables. To use this example, replace the *user input placeholders* with your own information.

```
spark.sql("CREATE NAMESPACE IF NOT EXISTS s3tablesbucket.my_namespace")
```