Nailing the interview takes an in-depth preparation and a huge amount of practice. We have compiled for you the most frequently asked 50 top tableau interview questions based on the difficulty level. You can go through them and brush up on your Tableau knowledge before the interview.
Also, we request you to mention more questions in the comments section below, in case you have attended a Tableau interview recently and you find them missing here.
Top Tableau Interview Questions
We have divided our Tableau interview questions into five difficulty levels:
Basic Tableau Interview Questions and Answers:
1. What is Tableau?
Tableau is a Business Intelligence (BI) and data visualization tool that not just helps in creating vizzes, generating reports, and helps in making presentations but also enables sharing them across to peers, friends, and groups within or outside an organization.
- BI and data visualization tool.
- Helps in creating vizzes, generating reports.
- Works as a sharing tool.
2. What are the other data visualization tools in the market?
While Tableau is the most sought-after data visualization tool in the market, below is the list of the other close contenders. Let’s start with Tableau:
- Zoho Analytics
- IBM Cognos Analytics
- Qlik Sense
- Microsoft Power BI
3. Explain the difference between Traditional BI tools and Tableau.
|Sl #||Traditional BI Tools||Tableau|
|1||Hardware limitations confine the output||Works independently|
|2||Complex technology involved||Dynamic and fast as it is based on Associative Search|
|3||Do not allow in-memory, multi-threaded, multi-core computing.||Offers support to in-memory feature when used with advanced technologies.|
|4||Constitutes a pre-defined view of data||Performs predictive analysis for different business operations.|
4. What are the different Tableau Products and which is the latest Tableau version?
There are five Tableau products in all:
1. Tableau Desktop
This essentially is the commercial edition of Tableau. There are two versions of the Desktop edition:
- Desktop Personal
- Desktop Professional
The Desktop product allows you to directly connect to a data source which could be a database like Oracle, AWS, MySQL, and others such as Microsoft Excel File, CSV, Google Spreadsheets, etc. Once the user can establish a connection, they can create data visualizations without any coding whatsoever. They can place multiple vizzes together to form an interactive dashboard.
2. Tableau Public
This is a free and open-source edition of Tableau. It has most of the functionalities of the Desktop edition, however, it differs in terms of establishing the connection with various databases to produce visualizations. Additionally, anyone can see these vizzes and reports published on the Server.
3. Tableau Server
It is an enterprise-level software. The Server product is essentially a sharing tool that enables distributing the visualizations created using the Desktop product in an organization. It ensures the utmost safety, security of the confidential data. Also, it enables quick database connection through live connections.
4. Tableau Online
This edition of Tableau enables sharing the visualizations and reports generated on the Desktop edition in the cloud, hosted by the Tableau group.
5. Tableau Reader
It’s a free Tableau edition that allows viewing the reports published on the Desktop edition as a static page. It allows you to filter and drill down the data but confines any kind of interaction or editing the vizzes.
Tableau’s latest version is 2020.2 released in February 2020.
5. What is the Tableau Server?
It is the Tableau hosting platform where the vizzes, reports, data sources can be saved in a secure environment. It is one of the five products offered by Tableau. The Server retains all the functionalities of other Tableau products. This essentially means that you can simply use the Server edition to open the vizzes without having to use the Desktop edition.
The Server allows the user to set permissions to determine who can access the vizzes and perform the edits from the others who can access but cannot edit the final presentations.
6. Name the different data types in Tableau?
Tableau supports the following datatypes:
- Boolean (T/F)
- Number (Decimal)
- Whole Numbers
- Date and Time
- Geographical values
7. Explain the different joins in Tableau?
Tableau supports 5 types of joins based on the method it follows to combine tables based on a common key. They are:
Inner join – The output table has the values which have matches from both tables.
Left Join – The output table has values from the left table which has matches in the right table.
Right Join – The output table has values from the right table which has matches in the left table.
Outer Join – The output table has the values from both the tables
Union – The output table has the rows of one table appended to another table involved in the union.
8. What are shelves in Tableau?
The areas on the top and left of the Tableau Workbook. These are the places where the user can build visualization by placing the fields on them.
9. Explain the difference between .twb and .twbx files in Tableau?
A .twb is simply an XML document that contains all the visualizations you have prepared on the Tableau workbook. It does not constitute data.
The .twbx is particularly a zipped file that contains .twb file along with the supporting files such as, data extracts and supporting images.
10. Can Tableau be installed in Mac OS?
One can install Desktop and Public on both Windows OS and macOS.
11. How many maximum numbers of tables you can join in Tableau?
The maximum number of tables you can join in Tableau is 32.
12. What is the maximum number of rows Tableau allows at any particular time?
There is no restriction on the number of rows you can access in the table. However, the Public edition allows only up to 1 million rows in the tables.
Tableau Interview Questions and Answers for beginners:
13. What are the various connections you can make with your datasets? How are they different?
The user can either connect live to the data source or fetch an extract data on Tableau. The extract is essentially a snapshot of the actual data from the database.
- Live – Establishing a live database connection enables computational processing of the data from the dataset. The queries will directly reach the database and any changes in the database will be updated in the visualization.
- Extract – An extract is the compressed snapshot of the actual data stored on the disk and loaded into memory that is used by the data engine for creating the vizzes. However, this snapshot of the data can be refreshed on set schedules either as a whole or can be appended. One of the ways to set these schedules is through the Server.
14. Explain sets in Tableau.
Sets are the customized fields in Tableau that are created based on the dimensions from the data source. They are essentially the subset of your data that can be created either manually or using the conditional logic.
That said, sets shine out when you apply the conditional logic that allows dynamically updated results. Meaning, if the underlying data changes, the sets are also updated.
Sets show the IN/OUT members in a set. That means, it creates the vizzes for members IN the set versus the member OUT of the set.
15. Explain groups in Tableau.
Groups in Tableau are used to make the visualizations simpler. Groups create another level of the hierarchy when you roll the members within a dimension into a group. A group formed shows up as a new dimension on the left.
However, groups are static. This means any updates in the data, the new members remain ungrouped.
16. What is a hierarchical field in Tableau?
A hierarchical field in Tableau is created to view the data at a more granular level. With hierarchical fields, one can efficiently drill down between the levels in the viz. For example, the user can create a hierarchical field of Region, State, and county.
17. What is the Tableau Data Server?
Tableau Data Server plays the role of an intermediary between the users and the data. The Tableau data server performs the following functions
- Uploads data extracts
- Preserves database connections
- Changes made in the datasets, calculated fields, parameters, can be saved and shared using a secure and standardized dataset.
- It allows making queries first on extracts (snapshots of actual data) than before actually transferring them on the local machines.
18. Explain Tableau Data Engine.
Tableau’s data engine ‘Hyper’ is an integral feature of Tableau introduced in Tableau 10.5. It is an in-memory analytical database developed to achieve instant query results, predictive performance on data uploaded and stored on the disk.
The job of a Data Engine is essentially to create, refresh, and query extracts 5X faster.
19. What is the concept of dual-axis?
Dual-axis is the special feature of Tableau where it allows the user to visualize the data in two scales in the same graph. Many websites show data in dual axis to depict comparisons between two different measures on a different scale but in the same graph.
20. What is the difference between continuous and discrete in Tableau?
There are two types of data in Tableau.
The data dimensions can be discrete or continuous and all measures are discrete or continuous.
Discrete – These are the distinct data separate from each other. For example, individual values in a range. The blue tabs represent the Discrete values. Example: Number of products sold in a category.
Continuous – This data is continuous data that can be represented using a finite or infinite interval than individual values. The green tabs depict the Continuous fields. Example: Time, profits in a region.
21. How do you explain the story in Tableau?
A story is a worksheet in Tableau that contains the order of all the other worksheets or dashboards included in the Tableau Workbook. Each story point can refer to a different worksheet or a dashboard, or the entire story can be narrating a single visualization at different stages, explaining the applied filters, etc.
Stories in Tableau show how the facts are connected, by providing the context, and show how a change in one context affects the outcome. Each worksheet in a story is a story point.
22. How to create stories in Tableau?
Although there are many ways yo apply the filter, we have listed the common method below:
- Click the story tab.
- Choose the size of the story from the lower-left corner of the worksheet. You can choose from the predefined sizes or create a custom size.
- The story thus created will get a default name from the worksheet, however, one can edit it by double-clicking on the title.
- Start building a story by dragging the worksheets on the left pane to the center on the pane.
- Add captions to build context.
- The text object can help you in highlighting the key takeaways of the story point which will appear when you hover the mouse over it.
- You can add filters or apply the sorting option to make the overall story more effective.
- Save the Tableau workbook to update the changes.
Mid Level Tableau Interview Questions and Answers:
23. Explain the difference between the treemap and the heat map.
One can essentially use the heat map when you have to compare two different measures using color and size.
A treemap also depicts a similar representation, however, it is more effective and powerful. That is mainly because it uses hierarchical data for representation and illustrates the part to whole relationships.
24. Explain the concept of filters in Tableau? How many different types of filters are there? Explain each.
Just as the name suggests, the users can apply Tableau filters to confine the data uploading from the database.
The various filters in Tableau are:
- Normal Filter – This is the traditional filter that restricts the flow of the data from the database for a particular dimension when the user drags that dimension into the ‘Filter’shelf.
- Quick Filter – This feature quickly shows all the filtering options when you right-click on either dimensions or measures. These quick filters almost make up for all the filtering needs.
- Context Filter – One can apply this filter to each worksheet. When a query request initiates from a worksheet, Tableau creates a temporary flat-table that includes all the values that are left out either by Custom SQL or context filter.
25. Explain the steps to remove “All” options from Tableau auto-filter.
The auto-filter option in Tableau has a feature that can be used to remove the ‘All’ option from the menu.
- Right-clicking on the down arrow under the quick filter heading will show up options.
- Scroll down to the ‘customize’ option.
- Uncheck the ‘Show “All” value’ option.
26. How to work on the calculated field in Tableau?
Follow the below steps:
- Click the down arrow symbol on the right to the Dimensions and select the option “Create Calculated Field” and an editor appears.
- Name the newly formed field and write a formula.
27. What is aggregation and disaggregation of data?
Aggregation – It is the feature in Tableau when the numeric fields or the Measures are placed in the Row/Column shelves, the summarized levels appear such as sum, Average, Count, Minimum, etc.
The user can easily determine the aggregation applied as Tableau shows it in front of the field when it is placed on the shelf. For example, SUM(Sales). The aggregation of measures is available only in the relational data sources.
Disaggregation – This allows the users to view the data row-wise especially when you are analyzing underlying trends, hidden patterns, or to find insights. For example, you might want to find the test scores of different categories of students who attended the exam. Here, you need to disaggregate the test scores to find which group, sub-group, or certain individuals who performed well.
28. What are the parameters in Tableau? Explain with an example.
A parameter could be any random value passed to a program for a specific purpose. It can be a string, a numeric, etc. The parameters allow you to view the data under a specific scenario that is not present as such in the data. The user can control the input value to visualize the effects.
Creating a parameter:
- Click on the small down arrow on the right to the Dimensions.
- Select the option “Create Parameter”.
- Enter the name for the parameter.
- Set the parameter. You can provide a comment on the right side of the dialog box for later use or a better understanding of the viewers.
29. How to check the underlying SQL Queries in Tableau?
There are two options to check the underlying queries in Tableau:
- By creating a performance recording – It records all the interactions the user makes with the Tableau workbook. The user can view the performance recording by:
- Help->Settings and performance->Start Performance Recording
- Help-Settings and performance -> Stop Performance Recording
- By Reviewing the logs on Desktop – C:\Users\Documents\My Tableau Repository. However, for a live connection to the data source, one can check the log.txt, tabprotosrv.txt. For an extract, one can check tdeserver.txt.
30. How to implement Performance Testing in Tableau?
Running Performance tests on Tableau is an integral part of implementing it. This is done by loading Testing Server with TabJolt. TabJolt is nothing but and “Point” and “Run” load generator which performs QA on Tableau. It can be installed by other open-source products as Tableau in itself doesn’t support it.
31. Name the different components of the dashboard.
Horizontal – The horizontal container essentially has all the features that allow the user to place the worksheets from left to right on the dashboard and also edit the height of the elements.
Vertical – The vertical container allows the user to place the worksheets from top to bottom on the dashboard and edit the width of all the elements at the same time.
Text – Refers to all text fields
Image – From here Tableau applies some code to extract images that are stored in the XML Tableau file.
Web – This has the hyperlink which points to a web page, or a file outside Tableau. This feature is used more to point to the information posted about the workbook outside Tableau.
32. What is the TDE file in Tableau?
It is essentially a Desktop file of Tableau that contains data extracted from MS Excel, CSV File, or MS Access. The .tde files are considered to be ideal for support analytics and data discovery.
The two features of .tde files are:
- TDE are columnar files
- The TDE files are smart and architecture aware. This means that from RAM to hard disk space, they put all parts to work based on the best-fit situation.
33. What are the different Tableau Files?
Workbooks: These hold worksheets, dashboard, and stories.
Packaged Workbooks: These contain the workbook, supporting data, and relevant background images.
Bookmarks: These contain single worksheets
Data Extraction files: Extracts are the locally saved snapshot of a part of the dataset or the entire dataset.
Data Connection files: These are XML files that just contain the information related to the connections.
Advanced Tableau Interview Questions and Answers:
34. How to add custom color to Tableau?
Color palette and effects are essentially a feature of Desktop, Server, and Online products of Tableau.
Colors are the feature in the marks card. Almost all the marks in the marks card have the default color blue even when there are no fields placed on color.
When any field from the discrete dimensions is added to the color on the marks card, Tableau assigns a color to each value of the filed.
To change the colors in the palette :
- Click the upper right corner of the color legend.
- In the Desktop version, click on Edit Colors option from the context menu. In the case of the Server edition or the Online edition, the Edit Colors dialog pops up automatically.
- Click on the values on the left under the Select Data Item.
- Pick a color in the palette on the right.
- Repeat for all the values you want to assign the colors.
- Click OK in the Desktop product. On the Server, Online editions you simply close the dialog box.
35. Can the users create relational joins without creating a new table in Tableau?
Absolutely. The users can create relational joins without creating a new table in Tableau.
36. How does one automate reports in Tableau?
One of the ways to refresh the live updates is by scheduling it on the Server. When you are publishing reports on the Server, you will encounter an option where you can schedule reports. All you need to do is select the time when you need Tableau to refresh the data.
37. What does Assume Referential Integrity mean?
To improve the query performance on Tableau, the user can select the Assume Referential Integrity from under the Data menu.
When the user selects this option, Tableau refers to the joined table only when any fields in the visualization specifically reference for it.
38. Explain the scenarios when you use joins vs blending in Tableau.
Joins are most preferred when data is streamed from a single data source.
Blending is more viable when more than one data source is involved and a left join is established between the primary and the secondary data source.
39. What is the default data blending join in Tableau?
Data blending is one of the most essential features of Tableau. When more than one data source comes into the picture to create the visualizations, Data Blending takes place.
By default, the blend is to the similar left outer join. However, by switching one data source from primary to secondary, the user can emulate right, inner joins.
40. Explain the difference between joining and blending in Tableau?
Join happens when the user tries to connect two or more tables from the same data source.
Blending comes into the picture when two data sources are involved.
41. What are Extracts and Schedules in Tableau server?
Data Extracts are the subsets of the data from the actual data source. The workbooks using the Extracts are 5x faster in creating the vizzes as compared to the live connections to the database as the copy of the extracted data is imported into the Data Engine.
Once the extracts are created, the reports can be saved on the Server. However, what if there are any changes in the actual dataset. The user needs to schedule the refresh so that the extracted data gets refreshed automatically. This can be set while publishing the workbook on the server where the user is allowed to set the schedules based on the number of times they want the data to be refreshed.
42. What is the blended axis in Tableau?
Multiple measures can be viewed using the same axis in Tableau.
To achieve blended axes, drag one measure on to an existing axis. Therefore, when you blend measure, you get a single row or a column and all the values for each measure are depicted along one continuous axis.
In the case of dual-axis, there are two axes on either side of the visualization.
43. Explain the DRIVE Program Methodology.
The DRIVE program methodology is to establish a sync between businesses and IT. Many companies adopt the various steps involved in the Tableau Drive methodology essentially to build an analytical culture in their organizations. These steps are iterative, following the agile methodology for faster and effective deployment of the analytical culture.
Tableau Interview Questions and Answers for experienced:
44. How to use a group in the calculated field?
- One way to use the group in the calculated field is if the user can create a group in the calculated field. However, one cannot use temporary groups in calculated fields.
- If a user creates a group in the secondary data source in data blending and if it is a calculated group.
- One can use a group in another workbook if they can copy-paste the calculation in the workbook in question.
45. Explain the differences between the published data source and embedded data source in Tableau.
Published Data Source: It contains information about an independent data source that is not linked with one workbook. Any number of workbooks can use this data source.
Embedded Data Source: It contains connection information about the workbook it is associated with.
46. How does one embed views on Webpages?
Users can embed views on webpages, blogs, social media, internet portals, wiki pages, etc. Embedded views get updated as and when there is a change in the underlying data or when the visualizations are updated on the Server.
These views have the same permission settings as assigned on the Server. For a person to view the embedded views should also have an account on the Server.
Contrarily, if your company has a core account on the server, it allows the guest account users also to access the embedded views. In this context, the guest users need not have a server account.
Follow the below steps to embed vies on a web page:
- First, the user needs to get the embed code of the view. For this, they have to copy the code included with the Share button on the top of the view. Paste the code on the web page. The user can disable the share button on the web page by setting the ‘showShareOptions’ parameter to ‘false’.
- For changing the default appearance of the view, such as the toolbars, buttons, etc, the users can change the parameter settings in the code.
47. Is Tableau the best software for a strategic acquisition?
Yes. Through the data visualizations, Tableau can help businesses in identifying the underlying defects. With the help of various views, they can plan and improvise their processes to drive the betterment of the company.
48. What happens if my license expires now? Will the others with whom I shared the dashboards and workbooks which I published in the server earlier will be able to view them?
If your server license expires, Tableau suspends your account and you cannot access any reports that you have shared or any other reports until you renew your subscription.
The others who have access to your publications can continue to view, however, the site administrator at your organization can move the ownership to others who have access to update the extracts.
49. While working on Tableau why does the error related to the Extract appears often?
This error is a warning to the user when they try to publish a report connected to the internal server or linked to a file located on a local drive within an organization’s network.
The user has to essentially create an extract before publishing it.
50. Imagine the scenario where you are using the Desktop edition and have a live connection with a database. You are required to press F5 for refreshing the visualization each time. Is there a way to automatically set the refresh mode without having to press F5?
Below is the simplest code for automatically refreshing the visualization in every 5 minutes. However, it requires you to download and install an open-source utility AutoHotKeys for the following script to work. This is when you are not publishing the viz on Server, but want to have it refreshed every 5 min.
SendMode Input; SetWorkingDir %A_ScriptDir% ;
SetTimer, PressTheKey, 300000