Attach Modes

MotherDuck Attach Modes: Workspace and Single modes

This guide explains MotherDuck's two connection modes: workspace and single. Workspace mode is designed for working with multiple databases persistently across sessions, while single mode connects to just one database.

Connection Modes

MotherDuck offers two connection modes: workspace and single. The mode you use determines how your attachments and detachments are handled and whether these changes are saved for future sessions.

• Workspace Mode: This is the default mode when you want to work with all attached MotherDuck databases. When you attach or detach a database in this mode, that change is remembered for your next session. This is useful when you consistently work with the same set of databases. Parallel connections to MotherDuck in workspace mode will keep their attachments in sync. E.g. detaching a database in one client in workspace mode will detach it in all other clients that are connected in workspace mode.
• Single Mode: This mode is for when you only want to work with a specific MotherDuck database. Any databases you attach or detach during this session will not affect your saved workspace for the next time you connect or interfere with attachment state of other parallel connections to MotherDuck. Single mode is for example useful if you want to connect from BI tools that only support a single attached database.

tip

You can't switch between modes in the middle of a session. The mode is set by the first command you use to connect to MotherDuck.

Connecting to MotherDuck with a connection string

When you first connect to MotherDuck in a session, the connection string you use determines the attach mode. This applies to most of clients, like the DuckDB CLI (duckdb 'md:...') and Python (duckdb.connect('md:...')).

• To connect in Workspace Mode (default):

  • Use md: or md:<database_name>.
  • This connects to your MotherDuck workspace, attaching all databases from your last saved session.
  • If you specify a database name, it becomes the active database.
  • Any changes to attachments (attaching or detaching databases) are saved and will be restored in your next workspace session.

• To connect in Single Mode:

  • Use md:<database_name>?attach_mode=single.
  • This connects only to the specified database, ignoring your saved workspace.
  • Attachment changes are temporary and will not be saved.
  • Note: You must specify a database name to use single mode. Connecting with md:?attach_mode=single is not allowed, as this mode requires a specific database target.

Connecting to MotherDuck using the ATTACH command

If you are already in a DuckDB session, but not connected to MotherDuck yet, your first ATTACH command that targets MotherDuck establishes the attach mode for that session.

• To connect in Workspace Mode:

  • Use ATTACH 'md:'.
  • This attaches your entire saved workspace.
  • The session is now in workspace mode, and any subsequent attachment changes will be persisted for future sessions.

• To connect in Single Mode:

  • Use ATTACH 'md:<database_name>'.
  • This attaches only the specified database.
  • The session is implicitly set to single mode. Attachment changes are not saved.
  • Once in single mode, you cannot attach the entire workspace using ATTACH 'md:'.

Tips & Tricks

Further Notes:

• You can also explicitly set the attach mode before connecting to MotherDuck.

  LOAD motherduck
  SET motherduck_attach_mode = 'workspace' -- or 'single'
  ATTACH 'md:foo'

• The MotherDuck UI is always connecting in workspace mode.