2 Cardinality Flashcards
What is the importance of relationships in Power BI?
Relationships ensure data integrity by enforcing referential integrity, enabling data exploration from multiple tables, and providing the basis for interactive filtering and slicing in reports.
Relationships allow users to drill down into data and answer specific questions.
Define ‘One-to-Many’ cardinality in the context of Power BI.
One row in Table A can be related to many rows in Table B, but each row in Table B is related to only one row in Table A.
This concept can also be viewed from the perspective of ‘Many-to-One’.
Give an example of ‘One-to-Many’ cardinality.
One customer can have many orders.
This illustrates how a single entity (customer) can relate to multiple instances of another entity (orders).
Give an example of ‘One-to-One’ cardinality.
One employee has one employee ID.
This shows a unique relationship between two entities.
Give an example of ‘Many-to-Many’ cardinality.
One student can enroll in many courses, and one course can have many students.
This demonstrates the complexity of relationships in data modeling.
What is the ‘Both’ cross-filter direction in Power BI?
The ‘Both’ direction allows filtering to occur in both directions between related tables.
While useful, it can impact performance with large datasets.
What is generally recommended regarding cross-filter direction?
‘Single’ direction is generally recommended unless bidirectional filtering is absolutely necessary.
This helps maintain performance and clarity in data relationships.
What is the significance of the Relationship View in Power BI?
The Relationship View is important for visualizing and managing relationships between tables.
It provides a clear overview of how data is interconnected.
What is the autodetect feature in Power BI?
The autodetect feature helps identify and create relationships automatically between tables.
While beneficial, it has limitations and may not always produce the desired relationships.
How can existing relationships in Power BI be edited?
Existing relationships can be edited by changing cardinality and cross-filter direction.
This allows for customization based on data requirements.
What are some data modeling best practices in Power BI?
Best practices include using descriptive column names, ensuring data consistency, and using a star schema (fact table and dimension tables).
These practices enhance clarity and usability in data models.
Fill in the blank: Relationships in Power BI enable users to ______ data from multiple tables simultaneously.
explore
True or False: ‘Many-to-One’ and ‘One-to-Many’ cardinalities are different.
False
