Asset Selection Syntax#

To specify an asset selection as a string, Dagster supports a simple query syntax. This selection syntax is accepted in a few different places:

The list and materialize commands in the asset command-line interface.
The asset filter text box on the asset graph page, in the UI.
The selection parameter of define_asset_job. (This parameter alternatively accepts an AssetSelection object, which supports more complex selections built from compositions of Python objects.)

It works as follows:

A query includes a list of clauses. Clauses are separated by commas, except in the case of the selection parameter of define_asset_job, materialize, and materialize_to_memory, where each clause is a separate element in a list.
A clause can be an asset key, in which case that asset is selected.
An asset key with multiple components can be specified by inserting slashes between the components.
A clause can be an asset key preceded by *, in which case that asset and all of its ancestors (upstream dependencies) are selected.
A clause can be an asset key followed by *, in which case that asset and all of its descendents (downstream dependencies) are selected.
A clause can be an asset key followed by any number of +s, in which case that asset and descendents up to that many hops away are selected.
A clause can be an asset key preceded by any number of +s, in which case that asset and ancestors up to that many hops away are selected.

Clause examples

some_asset: select "some_asset" itself
my/prefixed/asset: select the asset whose AssetKey in Python is AssetKey(["my", "prefixed", "asset"])
*some_asset: select "some_asset" and all ancestors (upstream dependencies).
some_asset*: select "some_asset" and all descendants (downstream dependencies).
*some_asset*: select "some_asset" and all of its ancestors and descendants.
+some_asset: select "some_asset" and its direct parents.
some_asset+++: select "some_asset" and its children, its children's children, and its children's children's children.