Modeling & relationships

Star schema, cardinality, filter flow. 8 cards. Click a card to flip, or use the arrow keys and space bar.

What is a star schema?
One fact table surrounded by dimension tables, each joined one-to-many from dimension to fact.
Default filter direction?
From the one side to the many side — dimension filters fact.
Why avoid bidirectional filtering globally?
It creates ambiguous filter paths and possible circular dependencies. Use CROSSFILTER in a measure instead.
What does USERELATIONSHIP do?
Activates an inactive relationship for the duration of one CALCULATE expression.
What is a role-playing dimension?
One dimension used in several roles — e.g. Date joined to OrderDate, ShipDate and DueDate.
Requirements for time intelligence?
A dedicated, contiguous Date table covering complete years, flagged with Mark as Date Table.
How do you fix a snowflaked dimension?
Flatten it into a single wide dimension in Power Query.
What is Dual storage mode for?
Dimensions in a composite model — served from memory when possible, queried at source when joined to DirectQuery facts.