To load a Parquet file from S3, the httpfs extension is required. This can be installed using the INSTALL SQL command. This only needs to be run once.

INSTALL httpfs;

To load the httpfs extension for usage, use the LOAD SQL command:

LOAD httpfs;

After loading the httpfs extension, set up the credentials and S3 region to read data. Firstly, the region where the data resides needs to be configured:

SET s3_region='us-east-1';

With the only the region set, public S3 data can be queried. To query private S3 data, you need to either use an access key and secret:

SET s3_access_key_id='<AWS access key id>';
SET s3_secret_access_key='<AWS secret access key>';

or a session token:

SET s3_session_token='<AWS session token>';

After the httpfs extension is set up and the S3 configuration is set correctly, Parquet files can be read from S3 using the following command:

SELECT * FROM read_parquet('s3://<bucket>/<file>');

For Google Cloud Storage (GCS), the Interoperability API enables you to have access to it like an S3 connection. You need to create HMAC keys and declare them:

SET s3_endpoint='storage.googleapis.com';
SET s3_access_key_id='key_id';
SET s3_secret_access_key='access_key';

Please note you will need to use the s3:// URL to read your data.

SELECT * FROM read_parquet('s3://<gcs_bucket>/<file>');

For Cloudflare R2, the S3 Compatibility API allows you to use DuckDB's S3 support to read and write from R2 buckets. You will need to generate an S3 auth token and update the s3_endpoint used:

SET s3_region="auto"
SET s3_endpoint='<your-account-id>.r2.cloudflarestorage.com';
SET s3_access_key_id='key_id';
SET s3_secret_access_key='access_key';

Note that you will need to use the s3:// URL to read your data from R2:

SELECT * FROM read_parquet('s3://<r2_bucket_name>/<file>');