Connecting & Preparing Data Flashcards

Which Tableau join type returns only the rows that have matching values in both tables?

Answer: Inner join

An inner join keeps only rows where the join keys match in both tables.

What does a left join return when there is no matching row in the right table?

Answer: The unmatched left rows with null values for right columns

A left join keeps all left rows and fills right-table columns with null where no match exists.

In Tableau, what is the main difference between a join and a relationship (noodle)?

Answer: Relationships are flexible and defer join logic until analysis

Relationships keep tables separate and determine the appropriate join contextually at query time.

Which connection mode in Tableau queries the source database directly each time the view is refreshed?

Answer: Live connection

A live connection sends queries to the source database in real time.

What file format does a Tableau data extract use?

Answer: .hyper

Modern Tableau extracts use the .hyper file format.

A union in Tableau combines tables by doing what?

Answer: Stacking rows from tables with similar structures

A union appends rows from multiple tables that share a similar column structure.

Which feature lets you automatically union files whose names match a pattern in a folder?

Answer: Wildcard union

A wildcard union matches multiple files by name pattern and appends them automatically.