Configure an external volume¶

Create an external volume¶

The steps to create an external volume depend on your cloud storage provider.

For instructions, see the following topics:

• Amazon S3

• Google Cloud Storage

• Azure Storage

Each external volume is associated with a particular Active storage location, and a single external volume can support multiple Iceberg tables. However, the number of external volumes you need depends on how you want to store, organize, and secure your table data.

You can use a single external volume if you want the data and metadata for all of your Snowflake-Iceberg tables in subdirectories under the same storage location (for example, in the same S3 bucket). To configure these directories for Snowflake-managed tables, see Data and metadata directories.

Alternatively, you can create multiple external volumes to secure various storage locations differently. For example, you might create the following external volumes:

• A read-only external volume for externally managed Iceberg tables.

• An external volume configured with read and write access for Snowflake-managed tables.

Verify an external volume¶

To check that Snowflake can successfully authenticate to your storage provider using an external volume that you’ve configured, call the SYSTEM$VERIFY_EXTERNAL_VOLUME function.

Specify the name of the external volume that you want to verify.

SELECT SYSTEM$VERIFY_EXTERNAL_VOLUME('my_s3_external_volume');

Set a default external volume at the account, database, or schema level¶

To set an existing external volume as the default to use for Iceberg tables, you can set the EXTERNAL_VOLUME parameter at the following levels:

Account:

Account administrators can use the ALTER ACCOUNT command to set the parameter for the account. If the value is set for the account, all Iceberg tables created in the account read from and write to this external volume by default.

Object:

Users can execute the appropriate CREATE <object> or ALTER <object> command to override the EXTERNAL_VOLUME parameter value at the database or schema level. The lowest-scoped declaration is used: schema > database > account.

In addition to the minimum privileges required to modify an object using the appropriate ALTER <object_type> command, a role must have the USAGE privilege on the external volume.

ALTER DATABASE my_database_1
  SET EXTERNAL_VOLUME = 'my_s3_vol';

CREATE ICEBERG TABLE iceberg_reviews_table (
  id STRING,
  product_name STRING,
  product_id STRING,
  reviewer_name STRING,
  review_date DATE,
  review STRING
)
CATALOG = 'SNOWFLAKE'
BASE_LOCATION = 'my/product_reviews/';