LIST_OBJECTS

A table-valued function (TVF) that lists objects and their metadata from Amazon S3. The function can use either a location object (recommended) or direct credentials to access the data. Each row in the output contains four columns: object_name (TEXT), object_type (TEXT), object_bytes (BIGINT), and file_timestamp (TIMESTAMPTZ).

Syntax 

-- Using location object (recommended)
LIST_OBJECTS (
  LOCATION => location_name
)
|
-- Using static credentials
LIST_OBJECTS (
  URL => <url>
  [, AWS_ACCESS_KEY_ID => <aws_access_key_id>]
  [, AWS_SECRET_ACCESS_KEY => <aws_secret_access_key>]
  [, AWS_SESSION_TOKEN => <aws_session_token>]
  [, AWS_ROLE_ARN => <aws_role_arn>]
  [, AWS_ROLE_EXTERNAL_ID => <aws_role_externakl_id>]
)

Parameters

Parameter Description Supported input types
LOCATION The name of a location object that contains the S3 URL and credentials. This is the recommended approach. See CREATE LOCATION for details. IDENTIFIER
URL The location of the Amazon S3 bucket containing your files. The expected format is s3://{bucket_name}/{full_file_path}. TEXT
AWS_ACCESS_KEY_ID The AWS access key ID. TEXT
AWS_SECRET_ACCESS_KEY The AWS secret access key. TEXT
AWS_SESSION_TOKEN The AWS session token. TEXT
AWS_ROLE_ARN The AWS role ARN. TEXT
AWS_ROLE_EXTERNAL_ID The AWS role external ID. TEXT

Return Type

The output is a table with four columns:

  • object_name (TEXT)
  • object_type (TEXT)
  • object_bytes (BIGINT)
  • last_modified (TIMESTAMPTZ)

Column Descriptions

  • object_name: Contains both the full path and the file extension.

  • object_type: Can be either “file” or “folder”.

    • If object_type = “folder”, the object_bytes and last_modified columns will contain NULL values, as folders do not have associated sizes or timestamps.

    • If object_type = “file”, the following apply:

      1. The last_modified column is populated from the LastModified attribute in Amazon S3. Note that AWS does not expose the creation timestamp, so the values in this column only differ from the creation time if an immutable object has been overwritten.
      2. The object_bytes column contains the size of the file in bytes.

Amazon S3 is not a traditional filesystem. In AWS, what is commonly referred to as “folders” is called “common_prefixes,” and what are typically considered “files” are referred to as “objects.”

Examples

Using LOCATION object to store credentials

Best practice

Firebolt recommends using a LOCATION object to store credentials for authentication.

The following code example retrieves all objects from the specified LOCATION using the LIST_OBJECTS function:

SELECT * FROM LIST_OBJECTS(
    LOCATION => my_location
);

Returns:

object_name object_type object_bytes last_modified
data/file1.csv file 1421277 2023-02-27 10:49:13+01
data/folder1/ folder NULL NULL

Using static credentials

The following code examples show how to list all objects (folders) that start with a specified prefix within an Amazon S3 bucket. You can specify either a part of the prefix or the full prefix. For example, the URLs ending with the prefixes fire or firebolt_sample_dataset both return identical results because both are valid matches for the firebolt_sample_dataset folder as follows:

SELECT * FROM LIST_OBJECTS(url => 's3://firebolt-publishing-public/help_center_assets/fire')

and

SELECT * FROM LIST_OBJECTS(url => 's3://firebolt-publishing-public/help_center_assets/firebolt_sample_dataset')

Both return:

object_name (TEXT) object_type (TEXT) object_bytes (BIGINT) last_modified (TIMESTAMPTZ)
help_center_assets/firebolt_sample_dataset/ folder NULL NULL

The following code example shows how to list all objects such as files, folders, and associated metadata, that start with a specified prefix in an Amazon S3 bucket:

SELECT * FROM LIST_OBJECTS(url => 's3://firebolt-publishing-public/help_center_assets/firebolt_sample_dataset/')

Returns:

object_name (TEXT) object_type (TEXT) object_bytes (BIGINT) last_modified (TIMESTAMPTZ)
help_center_assets/firebolt_sample_dataset/players.json file 1,421,277 2023-02-27 10:49:13+01
help_center_assets/firebolt_sample_dataset/levels.csv file 83,596 2023-02-27 11:06:52+01
help_center_assets/firebolt_sample_dataset/tournaments.csv file 83,351 2022-12-15 15:34:14+01
help_center_assets/firebolt_sample_dataset/games.json file 872 2023-02-27 13:18:54+01
help_center_assets/firebolt_sample_dataset/rankings/ folder NULL NULL
help_center_assets/firebolt_sample_dataset/playstats/ folder NULL NULL

The following code examples show how to list all objects such as files and associated metadata, that start with a specified prefix in an Amazon S3 bucket. The URLs ending with the prefixes lev or levels.csv return identical results because both are valid matches for the levels.csv file as follows:

SELECT * FROM LIST_OBJECTS(url => 's3://firebolt-publishing-public/help_center_assets/firebolt_sample_dataset/lev')

and

SELECT * FROM LIST_OBJECTS(url => 's3://firebolt-publishing-public/help_center_assets/firebolt_sample_dataset/levels.csv')

Both Return:

object_name (TEXT) object_type (TEXT) object_bytes (BIGINT) last_modified (TIMESTAMPTZ)
help_center_assets/firebolt_sample_dataset/levels.csv file 83,596 2023-02-27 11:06:52+01

The following code example shows how to use your Amazon credentials to list objects in an Amazon S3 bucket that is not publicly accessible:

SELECT * FROM LIST_OBJECTS(url => 's3://example_bucket/foo.csv', AWS_ACCESS_KEY_ID => 'my_key_id', AWS_SECRET_ACCESS_KEY => 'my_secret_key')

Returns:

object_name (TEXT) object_type (TEXT) object_bytes (BIGINT) last_modified (TIMESTAMPTZ)
foo.csv file 10 2024-06-12 9:30:00 UTC