Tableau Interview Question/Answer Part-3
Q1: Which one is better? Extract or Live connection?
Ans: Extract connection is better than live connection because extract connection can be used from anywhere, anytime without connecting to database. We can construct our own visualizations on it irrespective of database connection.
Q2: What is the difference between bar chart and column chart in Tableau?
Ans: Both are used to compare two or more values. However, their difference lies in their orientation. A Bar chart is oriented horizontally whereas the Column chart is oriented vertically. Both the Bar and the Column charts display data using rectangular bars where the length of the bar is proportional to the data value.
Q3: What is a Stacked Bar chart and Stacked Column Chart?
Ans: Stacked Bar Chart composed of multiple bars stacked horizontally, one below the other. The length of the bar depends on the value in the data point. Stacked bar chart make the work easier, they will help us to know the changes in all variables presented, side by side. We can watch the changes in their total and forecast future values. Stacked Column Chart composed of multiple bars stacked vertically, one on another. The length of the bar depends on the value in the data point. A stacked column chart is the best one to know the changes in all variables. This type of charts should be checked when a number of series is higher than two.
Q4: Explain the disaggregation and aggregation of data in Tableau?
Ans: Aggregation → The process of summarizing the data and viewing a single numeric value is called aggregation.
Example – sum/avg of salary for each employee
Disaggregation →The process of viewing each transaction for analyzing all the measures both dependently and independently. Example – individual salary transactions for each employee.
Q5: Difference between dual & blended axis?
Ans: Dual axes:
● Dual axes are two independent axes that are layered on top of each other. According to Tableau,
dual axes allow you to compare multiple measures. Dual axes are useful when you have two
measures that have different scales.
● Dual axis is used to show 2 measures in a single graph. It allows you to compare 2 measures at
once. Many websites like indeed use this dual axis to show the comparisons and growth rate.
Blended axis:
● Multiple measures can share in a single axis so that all the marks will be shown in a single pane.
We can blend measures by dragging the 1st measure on one axis and 2nd on the existing axis.
Q6: What is story in Tableau?
Ans: A story is a sheet that contains a sequence of worksheets or dashboards that work together to convey information. You can create stories to show how facts are connected, provide context, demonstrate how decisions relate to outcomes, or simply make a compelling case. Each individual sheet in a story is called a story point.
Q7: What are groups?
Ans: 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.
Q8: What is a hierarchical field?
Ans: A hierarchical field in tableau is used for drilling down data. It means viewing your data in a more granular level.
Q9: State some reasons for low performance of Tableau? Explain in detail.
Ans: Following are the reason for low performance:
1. Filters - filters need to create an extra query and if it is used in large numbers and inefficiently
then they can reduce the performance. So, it is advised to use filters whenever it is mandatory
2. Live connection - Tableau extract works much better in comparison with live connection.
3. Data sources - a wrong query to a wrong data source can reduce performance. Also data source’s
performance can also affect Tableau’s performance
Q10: How do we do testing in Tableau?
Ans: Yes, we can do testing in Tableau by using the tools and the easiest way is using the desktop
application. We need to check it before we publish in the Tableau server.
Ans: Extract connection is better than live connection because extract connection can be used from anywhere, anytime without connecting to database. We can construct our own visualizations on it irrespective of database connection.
Q2: What is the difference between bar chart and column chart in Tableau?
Ans: Both are used to compare two or more values. However, their difference lies in their orientation. A Bar chart is oriented horizontally whereas the Column chart is oriented vertically. Both the Bar and the Column charts display data using rectangular bars where the length of the bar is proportional to the data value.
Q3: What is a Stacked Bar chart and Stacked Column Chart?
Ans: Stacked Bar Chart composed of multiple bars stacked horizontally, one below the other. The length of the bar depends on the value in the data point. Stacked bar chart make the work easier, they will help us to know the changes in all variables presented, side by side. We can watch the changes in their total and forecast future values. Stacked Column Chart composed of multiple bars stacked vertically, one on another. The length of the bar depends on the value in the data point. A stacked column chart is the best one to know the changes in all variables. This type of charts should be checked when a number of series is higher than two.
Q4: Explain the disaggregation and aggregation of data in Tableau?
Ans: Aggregation → The process of summarizing the data and viewing a single numeric value is called aggregation.
Example – sum/avg of salary for each employee
Disaggregation →The process of viewing each transaction for analyzing all the measures both dependently and independently. Example – individual salary transactions for each employee.
Q5: Difference between dual & blended axis?
Ans: Dual axes:
● Dual axes are two independent axes that are layered on top of each other. According to Tableau,
dual axes allow you to compare multiple measures. Dual axes are useful when you have two
measures that have different scales.
● Dual axis is used to show 2 measures in a single graph. It allows you to compare 2 measures at
once. Many websites like indeed use this dual axis to show the comparisons and growth rate.
Blended axis:
● Multiple measures can share in a single axis so that all the marks will be shown in a single pane.
We can blend measures by dragging the 1st measure on one axis and 2nd on the existing axis.
Q6: What is story in Tableau?
Ans: A story is a sheet that contains a sequence of worksheets or dashboards that work together to convey information. You can create stories to show how facts are connected, provide context, demonstrate how decisions relate to outcomes, or simply make a compelling case. Each individual sheet in a story is called a story point.
Q7: What are groups?
Ans: 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.
Q8: What is a hierarchical field?
Ans: A hierarchical field in tableau is used for drilling down data. It means viewing your data in a more granular level.
Q9: State some reasons for low performance of Tableau? Explain in detail.
Ans: Following are the reason for low performance:
1. Filters - filters need to create an extra query and if it is used in large numbers and inefficiently
then they can reduce the performance. So, it is advised to use filters whenever it is mandatory
2. Live connection - Tableau extract works much better in comparison with live connection.
3. Data sources - a wrong query to a wrong data source can reduce performance. Also data source’s
performance can also affect Tableau’s performance
Q10: How do we do testing in Tableau?
Ans: Yes, we can do testing in Tableau by using the tools and the easiest way is using the desktop
application. We need to check it before we publish in the Tableau server.
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