Data visualization is a hot and upcoming career in the computer science field. A part of the data science branch, data visualization is one of the last steps carried out to distill the findings gleaned from data into charts, graphs, and other visual delights.
It is a highly creative career path. If you have an eye for visual aesthetics and a flair for technical, you are no longer relegated to animations or graphic designing. You can be a part of the core computer science field and also leverage your artistic talents.
If you are a big ‘yes!’ to this career opportunity, then the questions below will help you get started by preparing you for the interview round.
Q 1) What is Tableau?
A 1) Tableau is a data visualization and business intelligence software. It is used to create a visual representation of data and has interactive, shareable dashboards.
Q 2) What is the Tableau Data Server?
A 2) The Tableau Server is the connecting line between the data and Tableau users. Using Tableau Data Server allows one to preserve database connections, upload data extracts, share data extracts, reuse field metadata, and reuse calculations. Thus, any changes made can be saved and shared with others. These changes can include those made to the parameters, definitions, aliases, data set, calculated fields. Overall, the dataset becomes secure and centrally managed.
Q 3) What are the different Tableau files available?
A 3) Workbooks: they hold at least 1 worksheet or dashboard
Packaged workbooks: it consists of a workbook along with background images and supporting local file data
Bookmarks: it is an easy way to quickly share your work since it contains a single spreadsheet
Data connection files: a small XML file with various connection information
Data extraction files: these are a local copy of a subset or entire data source
Q 4) What are the different available Tableau products?
A 4) These are:
Using Tableau Desktop, you can directly connect to data from your data warehouse. Queries can be performed without writing a single line of code and pictures of data are translated into optimized queries.
Whatever visualizations are built in Tableau Desktop can be viewed here. Data can be drilled down or filtered, but it cannot be modified or used to perform any kind of interaction.
This is a free Tableau software. You can create your visualizations here, but you’ll need to save the workbook or worksheets in the Tableau Server where they can be viewed by anyone.
Great for enterprise needs. Through this web-based server, you can create whatever dashboards you create on Tableau Desktop.
A hosted version of Tableau Server, Tableau Online improves the quality and speed of business intelligence.
Q 5) Which are the different data types in Tableau?
- Date and time
- Text/ string
- Number- whole and decimal
- Geographical values
Q 6) What is the maximum number of tables you can join in Tableau?
A 6) 32
Q 7) What are the different types of joins in Tableau?
A 7) They are the same as in SQL and include:
- Right join
- Left join
- Inner join
- Full outer join
Q 8) What are the different types of connections you can make with the dataset in Tableau?
A 8) Connection with your dataset can either be made live or we can extract the data to Tableau, too.
If we choose the live option, then we can make use of the data set’s storage and computational power. All new queries will go to the database and will be shown as new or updated data.
On the other hand, if we choose to extract data onto Tableau, the extracted data is used by the data engine anywhere without any connection. The extract is basically a static snapshot.
Q 9) What are shelves?
A 9) Shelves are named areas to the left an top of the view. When you place a field on a shelf, a view a built. Certain shelves are possible only with certain mark types.
Q 10) What is the difference between a heat map and a tree map?
A 10) Using heat maps, we can compare two different measures together. It can be used for comparing categories with color and size.
A tree map performs the same function, albeit, in a different way since it illustrates hierarchical data and part-to-whole relationships. This is a more powerful visualization method.
Q 11) What is the difference between joining and blending?
A 11) The term joining is used when data is combined from the same data sources. Example: from 2 sheets in Excel.
The term blending, on the other hand, is used when data sources are different. Example: a sheet in Excel and a table from Oracle.
Q 12) What are the limitations in Tableau?
- Can’t define the width and columns individually
- Parameters don’t accept multiple sections
- For a worksheet view, you can’t control the display, selection, and sorting of columns in the view data option
Q 13) What is forecasting in Tableau?
A 13) In Tableau, forecasting means to predict the value of a measure. Although there are various methods for forecasting, in Tableau, we can only use exponential smoothing.
Q 14) Which file contains extracts and background images along with an XML document?
A 14) A .twbx file which is a zipped archive of a .twb file and other external files like the ones mentioned above. A .twb file is an XML document, which does not contain any data but does contain all the selections and layout made in the Tableau workbook.
The above list of questions is not exhaustive but is meant to be a starting point for your interview practice. The best preparation you can do is to refine your Tableau skills do that you know the ins and outs of this amazing business intelligence software. Then, no matter the question asked- you will be 200% ready.