Data Connections and Preparation Flashcards

What is the main advantage of using a 'Published Data Source' on Tableau Server compared to embedding the connection in the workbook?

Answer: Multiple workbooks can share and reuse a single centrally managed data source

Publishing a data source to Tableau Server allows multiple workbooks to connect to one centrally governed source, simplifying updates and ensuring data consistency.

In Tableau, what does 'pivoting' columns do in the data source view?

Answer: Converts multiple columns into two fields: a field name column and a value column

Pivoting in Tableau transforms wide-format data by converting selected columns into a 'Pivot Field Names' column and a 'Pivot Field Values' column, making the data taller and more analysis-friendly.

Which of the following describes a scenario where data blending is preferred over a join in Tableau?

Answer: When you need to combine data from two different data sources at different levels of granularity

Data blending is ideal when combining data from different sources at different granularities, as it aggregates the secondary source before linking, avoiding row duplication issues from joins.

What does the 'Replace References' option do when you replace a data source in a Tableau workbook?

Answer: Maps fields from the old source to matching fields in the new source automatically

'Replace References' attempts to automatically remap all workbook field references from the old data source to matching fields in the new data source by name and type.

A Tableau user needs to connect to a REST API that has no native Tableau connector. What is the recommended approach?

Answer: Build or use a Web Data Connector (WDC) to fetch and pass data to Tableau

Web Data Connectors (WDC) are the standard Tableau mechanism for connecting to REST APIs and other web-based data sources not covered by native connectors.

When Tableau detects an ambiguous relationship (a many-to-many relationship between two tables), what is the recommended best practice?

Answer: Create a bridge or junction table to resolve the many-to-many relationship

Many-to-many relationships should be resolved by introducing a bridge/junction table that breaks the relationship into two one-to-many relationships, preventing row duplication.

Which setting in a Tableau extract allows you to keep only the most recent N rows of data, useful for rolling-window dashboards?

Answer: Incremental Refresh with a date filter

Incremental Refresh configured with a date-based condition lets you continuously add only new rows since the last refresh, maintaining a rolling window of recent data efficiently.