Attach to a DuckDB Database over HTTPS or S3

You can establish a read-only connection to a DuckDB instance via HTTPS or the S3 API.

Prerequisites

This guide requires the httpfs extension, which can be installed using the INSTALL httpfs SQL command. This only needs to be run once.

Attaching to a Database over HTTPS

To connect to a DuckDB database via HTTPS, use the ATTACH statement as follows:

ATTACH 'https://blobs.duckdb.org/databases/stations.duckdb' AS stations_db;

Since DuckDB version 1.1, the ATTACH statement creates a read-only connection to HTTP endpoints. In prior versions, it is necessary to use the READ_ONLY flag.

Then, the database can be queried using:

SELECT count(*) AS num_stations
FROM stations_db.stations;

num_stations
578

Attaching to a Database over the S3 API

To connect to a DuckDB database via the S3 API, configure the authentication for your bucket (if required). Then, use the ATTACH statement as follows:

ATTACH 's3://duckdb-blobs/databases/stations.duckdb' AS stations_db;

Since DuckDB version 1.1, the ATTACH statement creates a read-only connection to HTTP endpoints. In prior versions, it is necessary to use the READ_ONLY flag.

The database can be queried using:

SELECT count(*) AS num_stations
FROM stations_db.stations;

num_stations
578

Connecting to S3-compatible APIs such as the Google Cloud Storage (gs://) is also supported.

Limitations

• Only read-only connections are allowed, writing the database via the HTTPS protocol or the S3 API is not possible.