Tableau interview questions and answers 👇

  1. Tableau Interview Questions


Tableau Interview Questions

1.

What are Measures and Dimensions?

Dimensions typically contain qualitative values (such as names, dates, or geographical data). And measures typically contain things you can measure, like numeric and quantitative values.

2.

What are shelves?

Tableau worksheets contain various named elements like columns, rows, marks, filters, pages, etc. which are called shelves. You can place fields on shelves to create visualizations, increase the level of detail, or add context to it.

3.

What is a hierarchical field?

Hierarchies arrange data fields in a level, for instance, a Geography hierarchy would have a region, country, state, city, area levels. Or, a Time hierarchy has a year, month, week, day as its levels. By creating hierarchies in Tableau, we set our data on different levels of detail and organize it

4.

What is Tableau Data Server?

The Data Server is a component of Tableau Server that will provide centralized management of Tableau Data Extracts and database connections. Tableau Data Extracts and Database connections can be managed centrally within Tableau Server and shared across workbooks.

5.

What is a dual axis?

You can compare multiple measures using dual axes, which are two independent axes that are layered on top of each other. Dual axes are useful for analyzing two measures with different scales.

6.

What is disaggregation and aggregation of data?

In aggregation, data values (particularly measure values) are combined together or aggregated to give a summarized or higher level of data for analysis. For instance, if we have a measure field containing sales values for different cities. We can aggregate these values to create averages, sums, etc. Aggregated fields are very useful in analysis.

When you disaggregate measures, you no longer are looking at the average or sum for the values in the rows in the data source. Instead, the view shows a mark for every row in the data source. Disaggregating data is a way to look at the entire surface area of the data.

7.

What are Extracts and Schedules in Tableau server?

Tableau Desktop authors and data stewards can create and publish extracts. Extracts are copies or subsets of the original data. Because extracts are imported into the data engine, workbooks that connect to extracts generally perform faster than those that connect to live data.

You can schedule refresh tasks for published extract data sources and published workbooks that connect to extracts. New schedules can be created by Tableau Server Administrators on the Schedules page.

8.

What is default Data Blending Join?

A default blend is equivalent to a left outer join. However, by switching which data source is primary, or by filtering nulls, it is possible to emulate left, right and inner joins.

9.

What is the difference between Joining and Blending?

Data blending simulates a traditional left join. The main difference between the two is when the aggregation is performed. A join combines the data and then aggregates. A blend aggregates and then combines the data.

10.

What is the difference between a Live Connection and an Extract?

Live and extracts are two ways you can make the data connection to the tableau. Live allows you real-time data while extracts are kind of batch which needs to be refreshed from time to time to get the updated data.

11.

What is a Calculated Field?

A calculated field is used to create new (modified) fields from existing data in the data source. It can be used to create more robust visualizations and doesn’t affect the original dataset.

12.

What is a Parameter in Tableau?

The parameter is a variable (numbers, strings, or date) created to replace a constant value in calculations, filters, or reference lines. For example, you create a field that returns true if the sales are greater than 30,000 and false if otherwise. Parameters are used to replace these numbers (30,000 in this case) to dynamically set this during calculations. Parameters allow you to dynamically modify values in a calculation.

Parameters can accept values in the following options:

  • All: Simple text field
  • List: List of possible values to select from
  • Range: Select values from a specified range
13.

What is Blended Axis?

Blended Axis in Tableau is useful to match two measured values against an equivalent axis.

14.

What is the purpose of Dual-axis?

Dual Axis allows you to compare measures, and this is useful when you want to compare two measures that have different scales.

15.

What is the Rank Function in Tableau?

The Rank function in Tableau accepts two arguments first, aggregated measure (or an expression) second, ranking order (ascending, or descending). Here the second argument is optional, and by default, it assigned as DESC (descending).

16.

What is the Level of Detail (LOD) Expression?

Level of Detail expressions (also known as LOD expressions) allow you to compute values at the data source level and the visualization level. However, LOD expressions give you even more control on the level of granularity you want to compute.

17.

What are continuous and discrete field types?

Continuous means "forming an unbroken whole, without interruption"; discrete means "individually separate and distinct." In Tableau, fields can be either continuous or discrete. When you drag a field from the Data pane to Columns or Rows, the values are continuous by default and Tableau creates an axis.

18.

What are sets?

Sets are custom fields that are created within Tableau Desktop based on dimensions from your data source. They are subsets of your data, which can be created manually or computed. Either dimensions or measures can be used to determine what is included or excluded from a set using conditional logic.

19.

How would you perform load testing in Tableau?

Load testing in Tableau is done to understand the server’s capacity with respect to its environment, data, workload, and use. It is preferable to conduct load testing at least 3-4 times in a year because with every new user, upgrade, or content authoring, the usage, data, and workload change.

Tabjolt was created by Tableau to conduct point-and-run load and performance testing specifically for Tableau servers. Tabjolt:

  • Automates the process of user-specified loads
  • Eliminates dependency on script development or script maintenance
  • Scales linearly with an increase in the load by adding more nodes to the cluster
20.

What is Tableau data engine?

The Data Server is a component of Tableau Server that will provide centralized management of Tableau Data Extracts and database connections. Tableau Data Extracts and Database connections can be managed centrally within Tableau Server and shared across workbooks.

21.

What is the difference between a tree and heat map?

A heat map is a great way to compare categories using color and size. In this, we can compare two different measures.

A treemap is a very powerful visualization, particularly used for illustrating hierarchical (tree-structured) data and for visualizing a part of or a whole relationship.

22.

What is a TDE file?

A Tableau data extract is a compressed snapshot of data stored on disk and loaded into memory as required to render a Tableau.

23.

How do you embed views into webpages?

  • Click the Share button at the top of a view (the Share button doesn't appear in embedded views if you change the showShareOptions parameter to false in the code.)
  • Click Copy Embed Code, then paste the code into your webpage.
24.

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.