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Sharing data in MotherDuck

MotherDuck's data sharing model has the following key characteristics:

  • Sharing is at the granularity of a MotherDuck database.
  • Sharing is read-only.
  • Sharing is done through share objects.
  • You can make shares discoverable and queryable by all users in your Organization.
  • You can create restricted shares, where access to each is managed with an Access Control List (ACL).
  • Alternatively, you can use hidden share URLs to limit access to specific people in your organization you share the URL with.
    • You can also configure the URL of a hidden share to be accessible by anyone with a MotherDuck account in the same cloud region as your Organization.
note

Shares are region-scoped based on your Organization's cloud region. Each MotherDuck Organization is scoped to a single cloud region that must be chosen at Org creation when signing up.

MotherDuck is available on AWS in three regions:

  • US East (N. Virginia): us-east-1
  • US West (Oregon): us-west-2
  • Europe (Frankfurt): eu-central-1

Sharing in MotherDuck works as follows:

  1. The data provider shares their database in MotherDuck by creating a share.
  2. The data consumer attaches said share, which creates a database clone in their workspace. The data consumer can now query this database.
  3. The data provider periodically updates the share to push updates to the database to data consumers.

Creating a share​

The first step in sharing databases in MotherDuck is to create a share, which can be done in both UI and SQL. Creating a share does not incur additional costs, and no actual data is copied or transferred - creating a share is a zero-copy, metadata-only operation.

Click on the "trident" next to the database you'd like to share. Select "share". Then:

trident

  1. Optionally, choose a share name. Default will be the database name.
  2. Choose whether the share should only be accessible by all users in your Organization, specified users in your Organization, or any MotherDuck user in the same cloud region who has access to the share link.
  3. Choose whether the share should be automatically updated or not. Default is MANUAL

Organization shares​

When creating a share, you may choose scope of access to this share:

  • Organization. Only users authenticated in your Organization will have access to this share.
  • Restricted. Only the share owner and users specified with GRANT commands can access the share.
  • Unrestricted. Any user signed into any MotherDuck organization in the same cloud region can access this share using the share URL.

Discoverable shares​

When creating a share, you may choose to make this share Discoverable. All authenticated users in your Organization can find this share in the UI.

You can create Discoverable shares that are Unrestricted, but only members of your Organization can find this share in the UI. Non-members can still access this share using the share URL.

Share URLs​

When you create a share, a URL for this share is generated:

  • If the share is Discoverable, members of your Organization can find this share without the share URL. Alternatively, they can use the URL directly.
  • If the share is Hidden (e.g. not Discoverable), other users will not be able to find the share URL. You will need to send this URL directly to the users with whom you want to share this data.

Consuming shared data​

The data consumer needs to attach the share to their workspace, thereby creating a read-only zero-copy clone of the source database. This is a free, metadata-only operation.

When you attach a share, it gets an alias that defaults to the source database name. If you already have a database with that name, the attach fails. Use AS to pick a different alias, or detach the conflicting database first. See share alias conflicts for details.

Views and fully-qualified table references​

If the shared database contains views, those views may reference tables using fully-qualified paths that include the original database name. For example, a view in a database called org_dwh might reference org_dwh.main.sales.

When you attach the share, make sure the database alias matches the original database name. Otherwise, the views fail because they can't resolve the original database name in your namespace.

-- The share was created from a database called "org_dwh".
-- Views inside reference the tables as "org_dwh.main.<table_name>".

-- This will cause view errors because the alias doesn't match:
ATTACH 'md:_share/org_dwh/id_abc123' AS dwh;

-- Use the original database name as the alias:
ATTACH 'md:_share/org_dwh/id_abc123' AS org_dwh;

This applies to any object in the shared database that uses fully-qualified references, including views, macros, and stored procedures.

Consuming discoverable shares​

If the data provider created a Discoverable share you have access to, you should be able to find this share in the UI.

  1. Select the share you want under "Shared with me".
  2. Optionally roll over the share to see the tooltip that tells you the share owner, when it was last updated, and share access scope.
  3. Click "attach".
  4. You can query the resulting database.

Consuming hidden shares​

If the data provider created a Hidden (e.g. non-Discoverable) share, they need to pass the share URL to the data consumer. The data consumer, in turn, needs to attach the share URL.

ATTACH 'md:_share/ducks/0a9a026ec5a55946a9de39851087ed81' AS birds;   # attaches the share as database `birds`

Updating shared data​

If during creation of the share, the data provider chooses to have the share update automatically, the share will be updated periodically. If the share was created with MANUAL updates, the data provider needs to manually update the share.

UPDATE SHARE birds;

Learn more about UPDATE SHARE and data replication timing and checkpoints.

Consuming updated data​

By default, shares automatically update every minute. However, if you need the most up-to-date data sooner, the consumer can manually refresh the share after the producer executes UPDATE SHARE.

To manually refresh the data:

REFRESH DATABASES;       -- Refreshes all connected databases and shares
REFRESH DATABASE my_share;  -- Alternatively, refresh a specific database/share

Lean more about REFRESH DATABASES.