Tableau Interview Questions

 

1. What is Tableau?

Tableau is a business intelligence software that allows interactive visualization and handling of large amounts of data. It is used by businesses around the world to crunch numbers and use the insights for growth and development. know Tableau online training

Tableau is one of the most important tools for data analytics and visualization only competed by Apache Superset, Qlik and Metabase to name a few alternatives.

2. Explain the different data types of Tableau.

There are 7 data types in Tableau

1. Boolean (True/False)
2. Date (Individual Value)
3. Date and Time
4. Geography
5. Text or String
6. Decimal Number
7. Whole Number

A visualization is typically made up of these seven types.

3. What are Measures and Dimensions?

Measures and Dimensions are attributes that define a specific dataset in Tableau.

Measures are measurable quantities of data which are analysed against dimensions. Any number of measures can be added to a single string, which is governed by dimensions. For example, an inventory of an online shop can have a total number of items, their prices, number of items sold historically, payment mode, etc. All of these can be considered measures. know more at Tableau online course

On the other hand, dimensions are basically descriptions which allow visualization to take place. They allow a user to describe a single metric in different ways. A dimension table consists of all these descriptions.

4. State the importance of data servers in Tableau

There are two functions of a data server in Tableau. One, it allows continuous syncing of all data – from datasets to past calculations, aliases to definitions – on the server which can then be accessed from anywhere. This allows for a more wholesome approach during any given task. Thus, it provides security and fast access.

Secondly, having a data server means one does not have to download all the required data to a local machine to run a visualization or a report. It can be pulled easily off the internet through the server.

5. What are the different filters in Tableau?

There are mainly three filters in Tableau which are used to restrict data pull. They are:

• Normal Filter – it is used to restrict a string of data from the base on selected measure or dimension
• Quick – it is used to change values dynamically across worksheets in a dashboard
• Context – it creates a temporary data source for use in any worksheet without disturbing the main dataset

Each of these filters has specific usage in any given reporting.

6. How to create a calculated field in Tableau?

On Tableau desktop version 2019.2, access the menu on the Data pane and click on ‘Create > Calculated Field’. Name the field and create the required formula. know more at Tableau training

7. What is a heatmap? Give an example.

A heatmap is a type of visualization used to demonstrate a set of data through varying shades of colours where the darkest shade of a specific colour denotes an extreme value (high intensity/density). It is typically used to compare two or more measures.

A quick example of a heatmap would be to understand the anatomy of the human body and observe the level of warmth depending upon the temperature of specific organs. If the red-yellow combination of colours is used, the areas that show red will denote the maximum temperature.

8. What is aggregation and dis-aggregation in Tableau?

Aggregation is the simple concept of averaging values in a given data set column. If a specific report contains the historical change in prices of a product, aggregation will help in finding its average value. In most cases, Tableau automatically aggregates a given set of data.

Disaggregation is the opposite of averaging, which can be helpful if a user wants individual data points. Both aggregated and disaggregated data can also be utilized in a single worksheet.

9. Differentiate between discrete and continuous.

Discrete and continuous are types of dimension flow in Tableau.

Discrete values are individual points that are counted as distinct values, separated from a batch. Example – number of states in a country.

Continuous values allow a user to utilize values within a finite or infinite interval. Examples – stock price movements of a company.

10. Give an example of a story on Tableau.

A story is a combination of worksheets or dashboards that convey a message as a whole.

An example of this would be a combination of two worksheets that depict the employee performance of a company. While one worksheet has performance metrics and summaries of employees in the levels L1 to L3, the second one can have the same data of employees in the levels L3 and L4 (upper management). Since the employee performance is interdependent, this can provide a bird’s eye view of the whole performance of the company’s workforce. know more at Tableau online training in Hyderabad`

This is used when the parameters and measures are different between the worksheets.

11. What is an embedded data source? How is it different from a published data source?

An embedded data source contains information that is connected to a workbook. A published data source works independently.

12. What is DRIVE Program Methodology?

It is a product of iterative sessions previously used and tested by enterprise deployments. It is based on best practises and allows a user to follow a specific set of actions to avoid errors and expedite reporting or visualization process.

13. Joins vs. Blending in Tableau.

Joining data means combining two sets of data from a single source (an Excel sheet, for example). Blending data involves the usage of two different sources (an Excel sheet and an Access report).

14. What is a TDE file?

TDE is a file extension type exclusive to Tableau which stores information sourced from third-party sources such as Microsoft Excel. It is similar to a spreadsheet. know more at Best Tableau online training

15. What is a dual-axis?

It is a function in Tableau that showcases two scales of two measures in a single graph. This is very similar to the function found on Microsoft Office products where a single graph has line and bar elements. In most cases, it has either two X or two Y axes.

A dual-axis is typically used to show trend lines and historical data. An example would be total revenue vs profit across 12 months.