Tableau Data Connections and Preparation 2 — Questions and Answers
Question 1: When connecting to a PDF file in Tableau Desktop, which of the following is a key limitation?
- Tableau cannot connect to PDFs at all
- Only text content is extracted; charts and images are ignored (Correct answer)
- PDF connections require a Tableau Server license
- PDF files must be under 10 MB
Correct answer: Only text content is extracted; charts and images are ignored
When Tableau connects to a PDF, it extracts tabular text data only; graphical charts and images within the PDF are not parsed into usable data.
Question 2: Which Tableau feature allows you to combine rows from two data sources that share the same fields and structure?
- Join
- Blend
- Union (Correct answer)
- Relationship
Correct answer: Union
Union stacks rows from tables with matching column structures into a single combined table, unlike joins which combine columns.
Question 3: In Tableau, what is the purpose of the 'Input' step in Tableau Prep Builder when building a flow?
- To define calculated fields before cleaning
- To specify the data source and initial connection settings (Correct answer)
- To output cleaned data to a published extract
- To merge multiple data sources via blending
Correct answer: To specify the data source and initial connection settings
The Input step in Tableau Prep Builder is where you connect to your data source and configure initial connection settings such as filters and sampling.
Question 4: What happens to NULL values when you create a wildcard union in Tableau?
- NULLs are automatically filled with zero
- Columns that don't exist in a particular sheet are filled with NULL (Correct answer)
- Wildcard unions reject sheets that contain NULL values
- NULLs are converted to empty strings automatically
Correct answer: Columns that don't exist in a particular sheet are filled with NULL
In a wildcard union, when sheets have differing columns, Tableau fills the missing column values with NULL for rows sourced from sheets that lack those columns.
Question 5: Which connection type should you choose if you want Tableau to store a copy of the data locally for faster performance?
- Live connection
- Extract connection (Correct answer)
- Published data source
- Web data connector
Correct answer: Extract connection
An Extract connection saves a snapshot of the data in Tableau's .hyper format locally, enabling faster query performance independent of the original data source.
Question 6: When editing a relationship between two tables in Tableau's data model, what is the default join type used behind the scenes?
- Inner join
- Left outer join (Correct answer)
- Full outer join
- Cross join
Correct answer: Left outer join
Relationships in Tableau use left outer joins by default, preserving all records from the primary table even when no match exists in the related table.
Question 7: A user wants to connect to a Google Sheets file in Tableau Desktop. Which authentication method is required?
- Username and password only
- API key stored in the workbook
- Google account OAuth sign-in (Correct answer)
- Tableau Server credential pass-through
Correct answer: Google account OAuth sign-in
Connecting to Google Sheets in Tableau Desktop requires authenticating via Google's OAuth flow using a Google account.
Tableau Data Connections and Preparation 2
When connecting to a PDF file in Tableau Desktop, which of the following is a key limitation?