Add a Snowflake Dimension
In AtScale, a snowflake dimension refers to a logical dimension comprised of columns coming from more than one physical dataset.
note
Note: Unhandled NULL values in key columns will result in incomplete
aggregate tables and unexpected query results. See the Custom Empty
Member
feature for more details.
Procedure
To add a snowflake dimension:
- Click the plus icon in the Dimensions panel to add a new empty dimension.
- Enter a name for the new dimension.
- Find the new dimension on the main canvas and double-click to open it in the dimension editor canvas.
- Drag all of the datasets that the snowflake dimension will use from the Library panel to the dimension canvas.
- Click the plus icon in the Hierarchies panel to add a new hierarchy.
- Drag the column that represents the dimension's key level attribute just below the hierarchy name in the Hierarchies panel. This creates a new level based on that dataset column.
- Continue adding levels by dragging dataset columns just above the previous level in the Hierarchies panel. A hierarchy should go from the most granular level on the bottom to the most general level on the top.
As you add a level from a column of a different dataset, AtScale will
automatically create the level relationship if the dataset in the level
below has a column of the same name. For example day.monthkey rolls up
to month.monthkey. If the relationship cannot be created, you'll have
to choose the dataset columns to link the new level to the one below it.