Most Popular Tableau Interview Questions
Data has become the new currency of trade and every organization big or small wishes to have a bite of it. In these fast-paced times and the ever-expanding domain of the data industry, predicting trends by analyzing data has become of the utmost importance. The analysis of huge data sets using Data visualization tools has become all the more imperative and the need of the hour, with a shortage in the demand for professionals who are skilled in this art of data analytics and their demand on a constant rise over the last few years.
Data Visualization has started a new trend in the data industry with the demand for skilled individuals soaring sky high. It allows the professional to make a smarter decision-making process with the least granular data that they can get or scrub all the ‘Noisy Data’ to gain meaningful insights into the business. Companies are ready to compensate any professional who can analyze the company’s data and put it on the path of growth and success. This blog will extremely be helpful to anyone who has completed a certified course in Tableau and wishes to start looking for a good-paying job that uses Tableau as it is core competence software. Make certain to go through the most frequently asked tableau interview questions:-
The different sub-products of Tableau are:-
Tableau Desktop – This is a premium version of the Tableau software. There are 2 plans for the software. The first one is for $ 999 for personal use for a year. The second option is $ 9,999 for professional use for a year. In both versions, the user using the Tableau desktop can create visualizations, all listed data sources can be connected using the app, access can be restricted to certain individuals, and many other features.
Tableau Online – Helps the user publish dashboards/reports in real-time with colleagues for easier and faster business intelligence solutions, with complete access to colleagues to leave ideas on the dashboard with their color tag without changing the original data.
Tableau Public – This product of Tableau allows the user to create visualizations but does not allow the document to be saved anywhere except the Tableau server where once the workbook is posted it is available for the public viewing purpose.
Tableau Reader – It is a free desktop application that allows the user to view visualizations and dashboards, without the access to edit or interact with the visualization created.
Tableau Server – This is enterprise-level software that allows the user to upload or save a visualization or dashboard in the cloud server allocated for the company.
Tableau supports the following data types:-
Measures are numeric metrics or quantifiable quantities of data, which are evaluated by dimension tables. Numbers are stored in a table that keys referring uniquely to the associated dimension tables. The table supports data storage at molecular levels and thus allows multiple records to be inserted at the same time. E.g., the Sales table can have a product key, customer ID key, several units sold key etc.
Dimensions are definitive attribute values for multiple dimensions of each attribute, defining multiple characteristics. A dimension table can have the reference of the key product from the table which may consist of the product name, size, color, type etc.
They are a lot similar to the joins one finds in SQL, it is a joining method for combining data on a common key
Inner join – the resulting table consists of values that have matches in both the tables
Left join – The table consists of all values from the left table and corresponding matches from the right table.
Right join – It is the other way around to the left join with the corresponding matches from the left table.
Outer join – The table consists of all values from both the tables
Union Join – This is another style of merging two or more tables by attaching rows of data from one table to another.
Merging data from two or more different sources is data blending. E.g., data from multiple sources i.e., MS Excel, SQL Server, Oracle etc are pooled into one Tableau workbook. In data blending, each data source consists of its own set of dimensions & measures.
Joining is when two or more tables from the same data source are amalgamated into one workbook. The combined tables or sheets consist of a common set of dimensions and measures.
A Tableau group is a one-dimensional representation of data, used to create a higher-level category by using lower-level category members. Tableau sets can have several conditions and may be grouped across multiple dimensions/measures.
The key disparity here is that all the groups will comprise of the same customers even if their profits change later on. In the case of sets, if the profit changes then the top five and bottom five customers will change accordingly.
Did you Know?
We cannot use groups in calculated fields, but we can use sets.
A parameter is a dynamic value that a user may choose, and also use to replace constant values in calculations, filters, and reference lines.
Heat Maps are used to compare categories using color and size. Using this method, the user may distinguish between two measures.
Tree Maps are used to represent hierarchical data. The space in this view is divided into rectangles that are sized and ordered by a measure.
A blended axis is used for merging two measures that share the same axis when they have the same scale.
This feature allows the user to compare measures which are useful when the user wishes to compare two measures that have different scales.
The difference between a blended axis and a dual-axis chart is that the blended axis uses the same scale, while a dual-axis can have two different scales or two marks cards.
Based on a measure, ranking is assigning a position within a category.
After signing into the Tableau server:-
If the field comprises of vacant values or if there are zeros or negative values on a logarithmic axis, Tableau would not be able to plot them. Tableau flashes an indicator in the lower right corner of the view, which once the user clicks are displayed the following options to choose from:
By following these steps any user can embed a webpage in a dashboard
Start by bringing up the map into view, which will showcase the states name
Now, when The Operator clicks on any state, it will bring up the webpage of that state and this is how a dashboard is made dynamic.
There are many ways to enhance the performance of a dashboard:
A maximum of 32 tables can be merged in Tableau.
The user can either connect live to their data set or extract data onto Tableau.
The advantage of using Tableau extract over a live connection is that extract may be used anywhere without any connection and The Operator can build their visualization without connecting to the database and impacting the functionality of the system.
They are designated areas in Tableau software, where the user may place the fields or the data with which The Operator chooses to create a visual.
Tableau server functions as the mediator between Tableau users and data. Tableau Data Server permits the operator to upload and communicate data extracts, sustain database links, as well as recycle calculations and field data. This means that any changes that the user makes to the dataset, calculated fields, parameters, aliases or definitions can be saved and shared with others. Permitting a centrally secured, managed, and standardized dataset. Additionally, the user may choose to pull up from the server’s resources to run queries on extracts without having to transfer them to the system in use.
Tableau Data Engine is a spectacular feature in Tableau. It is an investigative database designed to achieve instant query response, predictive performance, integrate seamlessly into existing data infrastructure with zero limitations to loadable data. If the user works with a large amount of data, it does not take time to import or create indexes and sort out data and after that speeds up the process. Tableau Data Engine is not in-memory technology. Post analysis the data is stored in a disk after being imported and the RAM is liberated for further tasks.
Filters in Tableau are used to restrict data from the database.
The different types of filters are:-
The process of viewing numeric values or measures at higher and more concise levels of the data is called Aggregation. When the Operator places a measure on a shelf, Tableau automatically accumulates the data, usually by summing it. The Operator can easily determine the aggregation applied to a field because the function always appears in front of the field’s name on being placed on a shelf. For example, Sales becomes SUM(Sales). The Operator can aggregate actions using Tableau only for relational data sources. Multidimensional data sources contain aggregated data only. In Tableau, multidimensional data sources are supported only in Windows operating systems.
Disaggregating the data allows the user to view every row of the data source which can be useful when The Operator is evaluating countermeasures that The Operator may want to use both independently and dependently in the view. E.g., The Operator may be evaluating the results from a product gratification survey with the age of applicants along one axis. The Operator can aggregate the Age field to determine the average age of participants or break down the data to determine what age participants were most satisfied with which of the products.
Data extracts are the primary copies of the original data from the data sources. The workbooks which use data extracts instead of using live database connections are quicker as the extracted data is imported to the Tableau Engine. After mining of data, the operator can publish the workbook which also publishes the extracts in Tableau Server. Nevertheless, the workbook and extracts will not refresh until the operator applies a scheduled refresh on the extracted data. Planned Refreshes are the programed tasks put in place for data extraction refreshers so that the data is refreshed automatically while publishing a workbook with extracts. This also removes the trouble of republishing the workbook every time the concerned data gets updated.
To view SQL queries, Tableau provides two options:-
Performance testing is an integral part of imparting Tableau in the user’s work culture. This can be done by load testing the Tableau server with ‘TabJolt’.
The auto-filter provides an option for removing ‘All’ options by simply selecting the down arrow in the auto-filter heading. The Operator can also scroll down to the ‘Customize’ section in the dropdown and then uncheck the ‘Show All’ value attribute. It can be activated by checking back the field again.
Adding a custom color refers to the use of a power tool in Tableau. On saving the .tps file restart The Operator Tableau desktop. From the measures, the pane drags the desired color onto the ‘Colour’ pane. From the color legend menu arrow, select ‘Edit Colours’. Once the dialog box opens, select the color The Operator wishes to customize The Operator Tableau in.
A .tde file is an extension file that consists of data being extrapolated from external sources like MS Excel, MS Access etc. There are two features of the TDE fabrication which makes them perfect for data discovery & analytics. The features are:-
To automate reports in tableau, the user would need to: –
In certain scenarios, query performance may be improved by choosing the ‘Assume referential integrity’ option from the Data menu. On using this option, Tableau would compile the joined table in the query only if special referencing is made by the fields in the visualization.
Data blending join allows the user to extract and compile data without the use of any special coding from several data sources into one Tableau Visual. A default data blend join functions as a left outer join but by switching the primary data source or by perforating the nulls it becomes possible to mimic left-right and inner joins.
The term ‘Story’ implies a sheet that consists of a sequence of worksheets or dashboards that work in tandem to convey a message. The user may create stories to show links between facts, provide context, showcase decision-making outcomes or simply make a compelling argument. Every single sheet in a story is known as a story point.
‘Discrete’ & ‘Continuous’ dimensions are the two types of data roles present in Tableau: –
There are several ways of creating stories in Tableau. Every story point can either be viewed on the same visualization or can be based on a distinct dashboard or visualization which can be seen at different stages with various annotations and marks filtered added to them. You can use stories to make a business argument or narrate an order of events. To create a story in Tableau the user may follow the following steps:-
Also, referred to a Tableau Drive, it is a methodology for clambering out self-service analytics. Tableau Drive is based on some of the best practices and successful enterprise deployments. The process relies on a much precise, iterative and responsive technique which is swift and efficient than the old school long cycle implementations.
It consists of connection information that is independent of any workbook and may be used in multiple workbooks.
It consists of connection information related to the workbook.
There are primarily 5 types of Tableau files: –
As an operator Tableau allows you to insert infographics in blogs, webpages, web applications, wiki pages, and intranet portals. Inserted visualizations refresh and get updated as the foundation data changes, or the workbook is updated on the Tableau server.
As the user following steps may be followed to insert visuals and to adjust their appearance:-
Get the embedded code provided with a visual: The Share button at the top of each visual comprises of an embed code that the user can copy and paste into the webpage. (The Share button does not appear in embedded views if you switch the ‘Show Share Options’ parameter to false in the coding)
Customize the embedded code: The operator may choose to customize the inserted code using factors that control the toolbar, tabs, and more.
As per the requirement, the data set should consist of fields about state, city, profit and sales fields. The next step is:-
Certainly, Tableau provides the user with data understandings to an extent other tools might not be able to. Also, it helps the user to strategize and point out inconsistencies and innovate the process for the benefit of the firm.
Yes, the user is allowed to do so using Tableau. But for higher performance using Extract is highly recommended.
Tableau Desktop is obtainable for both Windows and Mac operating systems.
Ms-Excel, VBA & MySQL
Using PowerBI &Tableau