Data Visualization is an important part of data analytics and it bridges the gap between humans and computers for extracting meaningful insight for the decision-making process. Here are the frequently asked interview questions and answers that help you ace the technical rounds of Tableau Jobs.
1.What are the limitations of traditional BI tools?
Traditional Business Intelligence tools are based on a complex set of technologies and the architecture contains a lot of hardware limitations. They will not support in-memory, multi-core, and multi-thread computing as they have a predefined view of data.
2.What are the advantages of Tableau?
Tableau does not have dependencies and it is based on the associate search that makes the data visualization process a dynamic and faster one. Tableau supports in-memory when it is being used with advanced technologies. It will utilize predictive analysis for various business operations.
3.What is Tableau?
Tableau is a popular and widely used business intelligence software that allows users to connect with respective data easily through visualizations of data using interactive and shareable dashboards.
4.What are the products available in the Tableau BI tool?
Tableau desktop, tableau reader, tableau public, tableau server, and tableau online are the products of the Tableau BI tool.
5.What is Tableau Desktop?
Tableau Desktop is self-service business analytics and data visualization product that can be used by anyone. It converts pictures of data into optimized queries and it helps the users to connect to data directly from their data warehouse for up-to-date data analysis.
6.Explain Tableau Server.
Tableau Server is an enterprise-level Tableau Software and the user can publish dashboards with Tableau Desktop and share them throughout the organization with a web-based tableau server. It connects with databases faster and effectively through live connections.
7.What is Tableau Reader?
Tableau Reader is the free desktop application used to open and view visualizations that are developed in Tableau desktop. The users can filter and view data but modification and interactions are not possible with Tableau Reader.
8.What is Tableau Public?
Tableau Public is the software that we can utilize to make visualizations. The workbook should be saved in Tableau Server so it can be viewed by anyone.
9.Define Tableau Online.
Tableau Online is the hosted version of Tableau Server and it helps the business intelligence faster and easier. The user can publish Tableau dashboards with Tableau Desktop for sharing them within the organization.
10.What are the datatypes to be used in Tableau?
Tableau supports various data types such as Boolean – True/False, Date – Date Values, Date & Time – Date and Time Stamp Values, Geographical Values – Geographical mapping, Text / String values, and Number – Decimal and Whole Numerical Values.
11.Explain about Measures and Dimensions
Measures are the numeric metrics of the data that can be analyzed by dimension table. Measures will be stored in a dimension table with foreign keys that can be referred uniquely to the associated tables. Dimensions are the attribute values for multiple dimensions of every attribute that defines various characteristics. A dimension table contains a reference to a product key from the table.
12.Differentiate the Extensions .twb and .twbx.
The .twb is an XML document that has all the sections and layout prepared in the Tableau workbook and it contains no data. While the .twbx is archived documents that contain external files like background images and extracts.
13.What are the various types of joins in Tableau?
The joins in Tableau are in like SQL joins and they are left join, right join, inner join, and full outer join.
14.What is the maximum limit for tables to join in Tableau?
We can join 32 tables in Tableau at the maximum.
15.What are the various connections that can be made with the dataset?
We can connect extract data or live data onto Tableau. In live connection, there are various benefits of computational processing and storage. If new queries are entered into the dataset, they will be reflected as new and will be updated within the data. In extract connection, it will make a static snapshot of data that can be used by Tableau’s data engine. The snapshot of the data can be refreshed on a recurring time as a whole or incrementally append in the data.
16.Define Shelves
Shelves are the named areas of the left and top of the view and we can build views by placing fields on the shelves. Some of them will be available when we select mark types. There are pages shelf, filter shelf, rows, and column shelf, and mark shelf in Tableau.
17.Explain Sets.
Sets are the custom fields that denote a subset of data based on particular conditions and they can also be based on a computed condition. The set will contain customers with sales over a particular threshold. Computed sets will modify the data per changes and a set can be based on a particular data point of the views of users.
18.What is meant by groups?
A group is the integration of dimension members that make higher-level categories. The user can work with a view that displays average test scores and the group joins together to create major categories.
19.Define Hierarchical field.
The hierarchical field is used for drilling down the data in tableau and it means viewing the data at a granular level.
20.How to create a calculated field using Tableau?
To create a calculated field in Tableau, first, we have to click the drop-down to the right of dimensions on the data pane and select “Create à Calculated Field” to open the calculation editor. Then, we should name the field and create a formula. Ex: IF(test, then, else, [unknown]).
21.What are the filters available in Tableau? Explain them.
In the tableau, filters are used to restrict the data from the database and the various filters are Quick Filter, Normal Filter, and Context Filter. Quick Filter is used to viewing the filtered data on a dashboard while changing the values dynamically during the execution time. A normal Filter is used to restrict the data from the database according to the selected dimension or measure. Context Filter is used to filter the data that is transferred to each worksheet of the tableau.
22.Define dual axis.
Dual Axis is the excellent factor of Tableau that helps users view two scales of measures in the particular group. It allows the users to compare two or more measures at once, with two independent axes layered on top of one another.
23.Differentiate TreeMap and Heat Map.
The tree Map used to compare the categories that have very powerful visualizations for illustrating hierarchical data and part-to-whole relationships while the heat map is used to compare categories with various colors and sizes for two different measures together.
24.Differentiate joining and blending
Joining is the term used to combine the data from the same source (from excel worksheet or oracle database) and blending is the term used to combine two completely defined data sources for the tableau report (from excel worksheet and oracle database).
25.How will you view underlying SQL Queries in Tableau?
There are two options in tableau to view the underlying SQL queries such as creating a performance recording and reviewing the Tableau desktop logs. For creating a performance recording, we should view performance metrics in a workbook created by Tableau.
Help -> Settings and Performance -> Start Performance Recording
Help -> Settings and Performance -> Stop Performance Recording
For reviewing the tableau desktop logs, we should check the location that is C:/User/My Documents/My Tableau Repository.
26.List out the components of Tableau Dashboard
The components of Tableau Dashboard are Horizontal, Vertical, Text, Image Extract, and Web [URL ACTION]. Horizontal contains to allow the designer to group the worksheets and dashboard events lift to right across the page and modify the height of all elements at once. Vertical Container allows the users to group worksheets and components top to bottom down to the page and modifies the elements at once. The text contains all textual fields. Image Extract is the component used to extract images. The URL action is a hyperlink that points to a web page.
27.How to automate reports in Tableau?
We need to publish the report to the Tableau server and there will be the option called schedule reports. If we select the time for automating the reports by refreshing the data.
28.What is a Drive program method?
Tableau Drive is a method that scales-out self-service analytics. Drive is based on the best outcomes of successful enterprise deployments. It relies on iterative and agile methods that are faster and effective for long-cycle deployment.
29.What are the various Tableau files?
There are five tableau files as Workbooks, Bookmarks, Packaged Workbooks, Data Extraction Files, and Data Connection Files.
Workbooks have one or more worksheets and dashboards, Bookmarks contains a single worksheet with an easy way to quick sharing option, the packaged workbook contains a workbook with any supporting local file data and background images, Data Extraction Files are a local copy of the entire data source, and Data Connection Files are small XML files that have connection information.
30.What is the difference between embedded data sources and published data sources?
Embedded Data Sources contain connection information that is associated with the workbook. While published data sources are having connection information that is independent of any workbook that can be used by various workbooks.
