Tableau Interview Questions

1. What is Tableau?

Tableau is a Business Intelligence software that allows anyone to connect to the respective data, then visualize and create interactive, shareable dashboards.

2. List out some of the new features introduced in Tableau 9.1?

The new features introduced in Tableau 9.1 includes the following:

• Data: With new web data connector, it makes data accessible from anywhere.
• Mobile: The new Tableau comes with high-resolution thumbnails, taking screenshot offline and high-level security for the data.
• Enterprise: Easy enterprise deployment with active directory synchronization.
• Visual Analytics: View proximity in the radial selection tool, also provides features like creating filter formulas and zoom control on your data.

3. What is Tableau public?

Tableau public is a free service that allows anyone to publish the interactive data to web.  Once it is there on web, anyone can interact with the data, download it or create their own visualization.

4. Can you create relational joins in Tableau without creating a new table?

Yes, one can create relational joins in Tableau without creating a new table.

5. Mention the different types of Tableau files.

Different types of Tableau files include the following:

• Workbooks: Workbooks hold one or more worksheets and dashboards.
• Bookmarks: It contains a single worksheet and it’s an easy way to quickly share your work.
• Packaged Workbooks: It contains a workbook along with any supporting local file data and background images.
• Data Extraction Files: Extract files are a local copy of a subset or entire data source.
• Data Connection Files: It’s a small XML file with various connection information Tableau-logo.

6. Mention the difference between published data sources and embedded data sources in Tableau.

The difference between published data source and embedded data source is that,

• Published data source: It contains connection information that is independent of any workbook and can be used by multiple workbooks.
• Embedded data source: It contains connection information and is associated with a workbook.

7. What are the characteristics to distinguish data source?

The data source are distinguished on the basis of following characteristics:

• Icon/name
• Connection type
• Connects to
• Live or last extract

8. When can we use Joins vs. Blending in Tableau?

If data resides in a single source, it is always desirable to use Joins. When your data is not in one place blending is the most viable way to create a left join like the connection between your primary and secondary data sources.

9. Explain Tableau Data Extract.

A Tableau data extract is a compressed snapshot of data stored on disk and loaded into memory as required to render a Tableau.  A TDE is a columnar store and reduce the input/output required to access and aggregate the values.

10. What is the difference between blending and joining in Tableau?

Following are the difference between blending and joining in Tableau:

• Joining term is used when you are combining data from the same source. for example, worksheet in an Excel file or tables in Oracle database.
• While blending requires two completely defined data sources in your report.

11. What is the difference between .twb and .twbx extension?

Following are the difference between .twb and .twbx extensions:

• A .twb is an xml document which contains all the selections and layout made you have made in your Tableau workbook. It does not contain any data.
• A .twbx is a ‘zipped’ archive containing a .twb and any external files such as extracts and background images.

12. What is the difference between Tableau and Traditional BI Tools?

Following are the difference between Tableau and Traditional BI Tools:

• Tableau provides easy to use, best in class, visual analytic capabilities but has nothing to do with the data foundation or plumbing. But with an integration with a SQL server it can be the complete package.
• On the other hand traditional BI tools have the mentioned capabilities but then you have to deal with significant amount of upfront costs. The cost of consulting, software and hardware is comparatively quite high.

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13. How many maximum tables can you join in Tableau?

You can join a maximum of 32 tables in Tableau.

14. What are the different filters in Tableau and how are they different from each other?

In Tableau, filters are used to restrict the data from database.

The different filters in Tableau are: Quick, Context and Normal/Traditional filter are:

• Normal Filter is used to restrict the data from database based on selected dimension or measure. A Traditional Filter can be created by simply dragging a field onto the ‘Filters’ shelf.
• Quick filter is used to view the filtering options and filter each worksheet on a dashboard while changing the values dynamically (within the range defined) during the run time.
• Context Filter is used to filter the data that is transferred to each individual worksheet. When a worksheet queries the data source, it creates a temporary, flat table that is uses to compute the chart. This temporary table includes all values that are not filtered out by either the Custom SQL or the Context Filter.

15. What are Extracts and Schedules in Tableau server?

Data extracts are the first copies or subdivisions of the actual data from original data sources. The workbooks using data extracts instead of those using live DB connections are faster since the extracted data is imported in Tableau Engine. After this extraction of data, users can publish the workbook, which also publishes the extracts in Tableau Server. However, the workbook and extracts won’t refresh unless users apply a scheduled refresh on the extract. Scheduled refreshes are the scheduling tasks set for data extract refresh so that they get refreshed automatically while publishing a workbook with data extract. This also removes the burden of republishing the workbook every time the concerned data gets updated.

16. How to view underlying SQL Queries in Tableau?

Viewing underlying SQL Queries in Tableau provides two options:

• Create a Performance Recording to record performance information about the main events you interact with workbook. Users can view the performance metrics in a workbook created by Tableau.
  • Help -> Settings and Performance -> Start Performance Recording
  • Help -> Setting and Performance -> Stop Performance Recording.
• Reviewing the Tableau Desktop Logs located at C:\Users\\My Documents\My Tableau Repository. For live connection to data source, you can check log.txt and tabprotosrv.txt files. For an extract, check tdeserver.txt file.

17. How to do Performance Testing in Tableau?

Performance testing is again an important part of implementing tableau. This can be done by loading Testing Tableau Server with TabJolt, which is a “Point and Run” load generator created to perform QA. While TabJolt is not supported by tableau directly, it has to be installed using other open source products.

18. Name the components of a Dashboard.

The components of a Dashboard are:

• Horizontal: Horizontal layout containers allow the designer to group worksheets and dashboard components left to right across your page and edit the height of all elements at once.
• Vertical: Vertical containers allow the user to group worksheets and dashboard components top to bottom down your page and edit the width of all elements at once.
• Text: All textual fields.
• Image Extract: A Tableau workbook is in XML format. In order to extracts images, Tableau applies some codes to extract an image which can be stored in XML.
• Web [URL ACTION]: A URL action is a hyperlink that points to a Web page, file, or other web-based resource outside of Tableau. You can use URL actions to link to more information about your data that may be hosted outside of your data source. To make the link relevant to your data, you can substitute field values of a selection into the URL as parameters.

19. How to remove ‘All’ options from a Tableau auto-filter?

The auto-filter provides a feature of removing ‘All’ options by simply clicking the down arrow in the auto-filter heading. You can scroll down to ‘Customize’ in the dropdown and then uncheck the ‘Show “All” Value’ attribute. It can be activated by checking the field again.

20. Mention whether you can create relational joins in Tableau without creating a new table?

 Yes, one can create relational joins in tableau without creating a new table.

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21. What is the DRIVE Program Methodology?

Tableau Drive is a methodology  for scaling out self-service analytics. Drive is based on best practices from successful enterprise deployments. The methodology relies on iterative, agile methods that are faster and more effective than traditional long-cycle deployment.

A cornerstone of this approach is a new model of partnership between business and IT.

22. How to create stories in Tableau?

There are many ways to create story in Tableau. Each story point can be based on a different view or dashboard, or the entire story can be based on the same visualization, just seen at different stages, with different marks filtered and annotations added. You can use stories to make a Business case or to simply narrate a sequence of events.

• Click the New Story tab.
• In the lower-left corner of the screen, choose a size for your story. Choose from one of the predefined sizes, or set a custom size, in pixels.
• By default, your story gets its title from its sheet name. To edit it, double-click the title. You can also change your title’s font, color, and alignment. Click apply to view your changes.
• To start building your story, drag a sheet from the Story tab on the left and drop it into the center of the view.
• Click Add a caption to summarize the story point.
• To highlight a key takeaway for your viewers, drag a text object over to the story worksheet and type your comment.
• To further highlight the main idea of this story point, you can change a filter or sort on a field in the view, then save your changes by clicking Update above the navigator box.

23. How to add Custom Color to Tableau?

Adding a Custom Color refers to a power tool in Tableau. Restart your Tableau desktop once you save .tps file. From the Measures pane, drag the one you want to add color to Color. From the color legend menu arrow, select Edit Colors. When a dialog box opens, select the palette drop-down list and customize as per requirement.

24. How to remove ‘All’ options from a Tableau auto-filter?

The auto-filter provides a feature of removing ‘All’ options by simply clicking the down arrow in the auto-filter heading. You can scroll down to ‘Customize’ in the drop-down and then uncheck the ‘Show “All” Value’ attribute. It can be activated by checking the field again.

25. What is story Tableau?

A story is a sheet that contains a sequence of worksheets or dashboards that work together to convey information. You can create stories to show how facts are connected, provide context, demonstrate how decisions relate to outcomes, or simply make a compelling case. Each individual sheet in a story is called a story point.