Tableau Interview Questions and Answers

What Are the Data Types Supported in Tableau?

Following data types are supported in Tableau:

Text (string) values
Date values
Date and time values
Numerical values
Boolean values (relational only)
Geographical values (used with maps)

What is Meant by ‘discrete’ and ‘continuous’ in Tableau?

Tableau represents data depending on whether the field is discrete (blue) or continuous (green).

Discrete – “individually separate and distinct.”
Continuous – “forming an unbroken whole without interruption.”

What Are the Filters? Name the Different Filters in Tableau.

Tableau filters are a way of restricting the content of the data that may enter a Tableau workbook, dashboard, or view.

The Different Types of Tableau Filters are:

Extract filters
Context filters
Data source filters
Filters on measures
Filters on dimensions
Table calculation filter

There Are Three Customer Segments in the Superstore Dataset. What Percent of the Total Profits Are Associated with the Corporate Segment?

Follow these steps:

Drag segment field to the rows shelf. Here, segment consists of Consumer, Corporate, and Home Office
Double-click on profit field under Measures.
Right-click on SUM (Profit) under marks card, select Quick Table Calculation, and click on Percent of the total. For more details Tableau Training

What is the disadvantage of Context Filters?

The Context Filter is not frequently changed by the user—if the Filter is changed, the database must be recomputed and the temporary table has to be rewritten, slowing performance.
When we set a dimension to context, Tableau creates a temporary table that will require a reload each time the view is initiated. For Excel, Access, and text data sources, the temporary table created is in an Access table format. For SQL Server, MySQL, and Oracle data sources, we must have permission to create a temporary table on our server. For a multidimensional data source, or cubes, temporary tables are not created, and Context Filters defined which Filters are independent and which are dependent.

Can we use non-used columns (columns that are not used in reports but used in data source) in Tableau Filters?

Yes! For example, in a data source, if we have columns like EmpID, EmpName, EmpDept, EmpDsignation, EmpSalary, and in reports we are using EmpName on columns and EmpSalary on rows, we can use EmpDesignation on Filters.

What is the benefit of Tableau Extract file over the live connection?

Extract can be used anywhere without any connection, and we can build our own visualizations without connecting to a database.

How to combine two Excel files with the same fields but different data (different years)?

Suppose, we have five different Excel files (2007.xls, 2008.xls, … 2011.xls) with the same fields (film name, genre, budget, rating, profitability, etc.) but with data of different years (2007 to 2011). Can someone tell me how can I combine the film name, genre, and profitability so that I can see the visualization of 2007 to 2011 in a single chart?

What are the different connections you can make with your dataset?

We can either connect live to our data set or extract data onto Tableau.

Live: Connecting live to a data set leverages its computational processing and storage. New queries will go to the database and will be reflected as new or updated within the data.
Extract: An extract will make a static snapshot of the data to be used by Tableau’s data engine. The snapshot of the data can be refreshed on a recurring schedule as a whole or incrementally append data. One way to set up these schedules is via the Tableau server.

The benefit of Tableau extract over live connection is that extract can be used anywhere without any connection and you can build your own visualization without connecting to database. For more skills Learn Tableau Online

What are shelves?

They are Named areas to the left and top of the view. You build views by placing fields onto the shelves. Some shelves are available only when you select certain mark types.

What are sets?

Sets are custom fields that define a subset of data based on some conditions. A set can be based on a computed condition, for example, a set may contain customers with sales over a certain threshold. Computed sets update as your data changes. Alternatively, a set can be based on specific data point in your view.

What are groups?

A group is a combination of dimension members that make higher level categories. For example, if you are working with a view that shows average test scores by major, you may want to group certain majors together to create major categories.

13. What is a hierarchical field?

A hierarchical field in tableau is used for drilling down data. It means viewing your data in a more granular level.

What is Tableau Data Server?

Tableau server acts a middle man between Tableau users and the data. Tableau Data Server allows you to upload and share data extracts, preserve database connections, as well as reuse calculations and field metadata. This means any changes you make to the data-set, calculated fields, parameters, aliases, or definitions, can be saved and shared with others, allowing for a secure, centrally managed and standardized dataset. Additionally, you can leverage your server’s resources to run queries on extracts without having to first transfer them to your local machine.

What is the difference between Tableau Workbook and Tableau Packaged Workbook?

Both the Tableau Workbook and Tableau Packaged Workbook are file types used in Tableau.

The Tableau Workbook type of files contains information about worksheets and dashboards that are present within a Tableau workbook. That is, all the information related to fields, aggregation types, styles, formatting, filters, etc are present in these files.

The Tableau Workbook files have an extension as .twb. We can only create these files from a live data connection and share them with users having access to that live connection. So, the .twb files contain metadata related to the existing data connection and does not contain the actual data from the workbook.

The Tableau Packaged Workbook file type is different from the .twb files as it contains both the metadata or information about the data of a workbook and the data extracted from the data source. They have an extension .twbx. The .twbx file type is used in place of a .twb file when you want to share a workbook with a user who does not have access to the live data connection. Thus, in this case, your .twbx file contains data extracted from the source along with the other information about the workbook.

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