Tableau Interview Question and Answer

1. What is Tableau?

Ans. Tableau software is a popular data visualization Business Intelligence (BI) tool. It connects easily to any data source, be it web-based data, warehouse, or Microsoft excel. Moreover, Tableau allows data visualizations to be generated as dashboards and worksheets.

2. What is LOD expression?

Ans. Level of Detail expressions or LOD expression offers a way to easily commute aggressions that are not at the level of detail of the visualization. With this, you can attach more than one dimension to any aggregate expression.

3. What are some of the new features introduced in Tableau 9.1?

Ans. New features introduced in Tableau 9.1 are –

• Visual analytics
• Mobile
• Data
• Enterprise
• 4. What is the difference between Tableau and Qlikview?

Ans. This is one of the most frequently asked Tableau interview questions.

Tableau:

• More connectors
• No coding is required
• Interface is simple
• Doesn’t render a feature to search content across all your data

Olikview:

• Easy to use and discover the hidden trends
• Offers a personal edition free
• Data is stored in qvd form from the performance point of view
• Great capabilities for processing data

5. What are the traits to differentiate data sources?

Ans. The data source is differentiated on the basis of the following characteristics:

• Connection type
• Icon/Name
• Connects to
• Live or Last extract

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

Ans. Yes, we can create relational joins without creating a new table.

7. What are the parameters?

Ans. They are dynamic values that can change constant values in calculations, reference lines, and filters.

8. Mention whether you can have multiple value selection in the parameter?

Ans. No, we can not have multiple value selection in the parameter.

9. Name some of the types of filters?

Ans. Normal filters, context filters, and custom filters are some of the types of filters.

10. What are the four different kinds of shelves in Tableau?

Ans. Rows, columns, filters, and pages are different kinds of shelves in Tableau.

11. Name some file extensions in Tableau?

Ans. Some of the file extensions in Tableau are –

• Tableau Datasource (.tds)
• Tabelau Bookmark (.tdm)
• Tableau preferences (.tps)
• Tableau workbook (.twb)
• Tableau Mapsource (.tms)

12. Explain Data blending?

Ans. Data blending is a method for coalescing data that supplements a table of data from one data source from columns of a table from another data source.

13. How many tables can you join?

Ans. One can join a maximum of 32 tables in Tableau.

14. What are the different components of a dashboard?

Ans. The different components of a dashboard are –

• Web
• Text
• Image Extract
• Horizontal
• Vertical

15. What is the TDE file?

Ans. TDE stands for Tableau data extract. It refers to the file that comprises data extracted from external sources like CSV files, MS Excel, or MS Access.

16. Name the different products Tableau offer?

Ans. Tableau offers products like –

• Tableau Desktop
• Tableau Reader
• Tableau Public
• Tableau Server

17. How to get the current date and time?

Ans. We get the current date and time by using the NOW () function.

18. Explain the Gantt chart.

Ans. Used for visualizing project schedules, Gantt Chart demonstrates the progress of the value of a task over a period of time.

19. What are the reasons for slow performance in Tableau?

Ans. One of the reasons is data source is slow in itself. This might be because your CSV file is too big or your database is old for reading. You can improve the Tableau experience by following ways:

• Use extracts
• Limit the amount of data you bring in – both rows and columns
• Switch data source using the “extract function”
• Pre-aggregate your data before bringing it into Tableau.

20. Which function is used to return the number of items in a group?

Ans. The count () function is used to return the number of items in a group.

21. Define sets.

Ans. Sets are used to define a subset of data depending on certain conditions. There are oodles of ways to create a set based on a filter that you have already mentioned.

22. How many types of Joins you can use in Tableau?

Ans. There are four types of Joins in Tableau:

• Left
• Right
• Inner
• Full outer

23. What do you mean by groups?

Ans. A mixture of dimension members that makes higher-level categories, Groups are used on calculated fields.

24. Explain Tableau Data Server.

Ans. Enabling you to share and upload data extracts and reuse calculations and field metadata, Tableau Data Server makes connecting to data transparent and much easier.

25. Difference between Measures and Dimensions?

Ans. Measures

• Generates axes when added to rows and columns shelves
• Dependent variable
• Stored in a table that has foreign keys
• Numeric units analyzed by dimension table

        Dimensions

• Descriptive attributes values defining multiple characteristics
• Generate headers when added to rows and columns shelves
• Independent variable
• Considered more complex

26. Which charts have you worked on?

Ans. This is among the most frequently asked Tableau interview questions.

Below is the complete list of chart types. You can name the ones you have worked on.

• Area Charts (Continuous & Discrete)
• Box-and-Whisker Plot
• Bubble Chart
• Bullet Graph
• Circle View
• Density Maps
• Dual-Line Chart (Non-Synchronized)
• Filled Map
• Gantt Chart
• Heat Map
• Highlight Table
• Histogram
• Horizontal Bar Chart
• Line Charts (Continuous & Discrete)
• Packed Bubbles
• Pie Chart
• Scatter Plot
• Side-by-Side Bar Chart
• Side-by-Side Circle View
• Stacked Bar Chart
• Symbol Map
• Text Table (Crosstab)
• Treemap

27. What is the maximum number of tables that can be joined in Tableau?

Ans. The maximum number of tables that can be joined in Tableau is 32. Table size is restricted to 255 columns.

28. What is the Tableau Data Engine?

Ans. Tableau Data Engine is an interface to extract all data from the machine and ensure the fastest response time. After the task is completed, the Tableau Data Engine can unleash its memory.

29. What is the Tableau Server Repository?

Ans. Tableau Server Repository is a database that stores server data like information about Tableau Server users, groups and assignments, permissions, projects, data sources. It also extracts metadata and refreshes information.

30. What are the different types of Dimensions?

Ans. There are nine different types of Dimensions –

1. Slowly Changing Dimensions
2. Rapidly Changing Dimensions
3. Junk Dimensions
4. Inferred Dimensions
5. Conformed Dimensions
6. Degenerated Dimensions
7. Role-Playing Dimensions
8. Shrunken Dimensions
9. Static Dimensions

31. What is VIZQL in Tableau?

Ans. VizQL is a visual query language. It sends queries directly to the data source and then expresses that data in the form of images. VizQL helps the user to understand data by abstracting the underlying complexities of query and analysis.

32. What is the Truth Table?

Ans. Truth Table is a collection of facts, determining the truth or falsity of a proposition. It works as a complete theorem-prover and is of three types –

• Accumulative truth Table
• Photograph truth Table
• Truthless Fact Table

33. What are the Default Geographic Roles?

Ans. This one is also among the most frequently asked Tableau interview questions –

Default Geographic Roles are –

Code (U.S)

CBSA/MSA (U.S)

general assembly Districts (U.S)

Cities

Country/Region

County

States/Provinces

nada Codes/ communicating Codes

34. What is a Hierarchical Field?

Ans. Tableau hierarchical field is a data model that organizes data into a tree-like structure. Here the data is stored as records, connected to one another through links. Tableau’s hierarchical field enables viewing the data at a more granular level.

35. What is the Dual Axis?

Ans. Dual axes are two independent axes layered on each other. Dual axes help a user to compare multiple measures simultaneously and is believed to be an excellent phenomenon supported by Tableau

36. How to do Performance Testing in Tableau?

Ans. Performance testing can be done by loading Testing Tableau Server with TabJolt, which is a “Point and Run” load generator for QA. While TabJolt sets a baseline. One can also use workbooks having calculations and use extracts as the data source for testing.

37. What is Assume Referential Integrity?

Ans. Assume Referential Integrity helps to improve query performance. When a user selects the Assume Referential Integrity option, Tableau will include the joined table in the query if it is suggested by fields in the view.

38. What is the use of Blended Axis?

Ans. Blended Axis is used when more than two measures are used in multi-lines graphs or charts and then presents in a single pane. It can be achieved by dragging one measure or axis and dropping it onto an existing axis.

39. What are Dimensions and Facts?

Ans.

Dimensions – Fields that cannot be aggregated

Facts – Refers to the measurable attributes of the data, such as numerical values, product names, geographical names, etc.

40. What is the Metadata?

Ans. Metadata refers to the detailed information about the data system and its contents. It helps to define the type of data or information that will be sorted.

41. What is the Heat Map?

Ans. It is the methodology to graphically represent the data using the color-coding technique. It represents different values of data. Higher values are presented in darker colors, thus the name.

42. What is the TreeMap?

Ans. Treemap is a visualization that has data organized hierarchically. It presents the data as a set of nested rectangles and their size and colors are respective to their values. In a treemap, parent rectangles are tiled with their child elements.

43. What is the Page Shelf?

Ans. Page Shelf is a powerful Tableau tool that contributes to controlling the output display. It breaks a view into a series of pages and displays an alternate view on each page for an easier understanding of the user and better data analysis.

44. What is the use of a Bin?

Ans. Bin is a user-defined gathering of measures in the information source. They are used to create a data range. It is similar to SQL Buckets.

45. What are the Filter Actions?

Ans. Filler activities send data in-between worksheets. Normally, filler actions transmit data from a selected mark to another sheet indicating related data. In the background, filler activities send information values from the pertinent source fields as filters to the target sheet.

46. What is the use of Global Filters and where can they be used?

Ans. Global Filters enable users to create filters at the dashboard level. They can be used as a part of sheets, dashboards, and stories.

47. What is Data Visualization?

Ans. In simpler terms, data visualization is a graphical representation of information and data. It enables the users to view and analyze data in a smarter way and use technology to draw them into diagrams and charts.

48. Wheasier to view and understand complex data in the form of charts or graphs, the trend of data visualizy should data visualization be chosen?

Ans. Since it is ation has picked up rapidly.

49. What is an Authentication Server?

Ans. An authentication server is a type of network server that validates and authenticates remote users or IT nodes to get to a network. It can inhabit a dedicated PC, an Ethernet switch, an access point, or a server-accessed system.

50. What is a Marks Card?

Ans. Marks Card is an essential component for visual examination. It helps to have control over the way data will be displayed in the view. Marks card enables to use of different sizes, colors, text, shapes, and details to encode the information.