50+ Tableau Developer Interview Questions and Answers

Filters are used to limit the data displayed in a visualization. There are different types of filters in Tableau.

• Types of filters include: dimension filters, measure filters, context filters, table calculation filters, and extract filters.

• Dimension filters limit the data based on specific dimensions, such as date or region.

• Measure filters limit the data based on specific measures, such as sales or profit.

• Context filters create a temporary table that can improve performance by...read more

Tableau supports various data types including string, integer, float, date, boolean, and geographic data.

• String: text data

• Integer: whole numbers

• Float: decimal numbers

• Date: date and time data

• Boolean: true/false data

• Geographic: latitude and longitude data

• Examples: 'John Smith' (string), 25 (integer), 3.14 (float), 01/01/2021 (date), true (boolean), (latitude, longitude) (geographic)

Aggregation is the process of combining data into a summary form, while disaggregation is the opposite, breaking down summary data into its individual components.

• Aggregation involves grouping data and performing calculations on the grouped data.

• Disaggregation involves breaking down summary data to reveal the individual data points.

• Aggregation is useful for analyzing trends and patterns at a higher level.

• Disaggregation is useful for exploring detailed data and identifying outl...read more

In Tableau, discrete and continuous are two types of data that can be used to categorize and analyze information.

• Discrete data consists of distinct, separate values that cannot be measured or divided further.

• Examples of discrete data in Tableau include categories like product names, customer segments, or regions.

• Continuous data represents measurements or values that can be divided infinitely and can take on any value within a range.

• Examples of continuous data in Tableau inclu...read more

There are three types of LOD (Level of Detail) calculations in Tableau: FIXED, INCLUDE, and EXCLUDE.

• FIXED LOD calculation is used to define a specific level of detail in the visualization.

• INCLUDE LOD calculation is used to include a dimension in the calculation while keeping other dimensions intact.

• EXCLUDE LOD calculation is used to exclude a dimension from the calculation while keeping other dimensions intact.

The latest version of Tableau is 2021.3.

• 2021.3 was released on September 14, 2021.

• New features include improved data modeling capabilities and enhanced analytics.

• Previous versions include 2021.2, 2021.1, and 2020.4.

Important aspects to consider while performance tuning of Tableau dashboards

• Optimizing data extracts and data connections

• Minimizing the number of filters and parameters

• Reducing the number of marks and data points displayed

• Using efficient calculations and aggregations

• Optimizing dashboard layout and design

• Using appropriate data types and data structures

• Regularly monitoring and analyzing performance metrics

Groups and sets are two ways to combine related data in Tableau for easier analysis and visualization.

• Groups allow you to combine related dimension members into higher-level categories.

• Sets are custom fields that define a subset of data based on conditions you specify.

• Groups are static and cannot be changed once created, while sets are dynamic and can be updated based on filters or calculations.

• Examples: Grouping states into regions (East, West, South, Midwest) using Groups. ...read more

Rolling 3, 6, 12 months refers to analyzing data over the past 3, 6, or 12 months, while YTD, MTD, QTD refer to year-to-date, month-to-date, quarter-to-date.

• Rolling 3, 6, 12 months involves looking at data over the past 3, 6, or 12 months, providing a trend analysis over a specific time period.

• YTD (Year-to-Date) refers to data from the beginning of the current year up to the present date.

• MTD (Month-to-Date) refers to data from the beginning of the current month up to the pres...read more

Data blending combines data from multiple sources while cross database join combines data from different tables in the same database.

• Data blending is used when data is stored in different sources like Excel, CSV, or databases.

• Cross database join is used when data is stored in different tables within the same database.

• Data blending creates a relationship between the data sources based on common dimensions.

• Cross database join combines data based on a common field or key.

• Data bl...read more

The order of operations of Tableau filters is context filters, extract filters, data source filters, and then dimension filters.

• Context filters are applied first, followed by extract filters, data source filters, and finally dimension filters.

• Context filters create a temporary table that only includes the data relevant to the filter.

• Extract filters are applied to the data extract before it is loaded into Tableau.

• Data source filters are applied to the entire data source.

• Dimens...read more

Tableau follows a client-server architecture with a three-tier structure.

• Tableau Desktop is the client application used for creating and publishing content.

• Tableau Server is the central server that manages user authentication, data sources, and content distribution.

• Tableau Online is a cloud-based version of Tableau Server.

• Tableau's three-tier structure includes the data source, the VizQL server, and the application server.

• Tableau's architecture allows for scalability and flex...read more

Rank assigns unique rank to each row, Dense Rank assigns consecutive rank without gaps.

• Rank leaves gaps in rank sequence if there are ties, Dense Rank does not

• Rank assigns unique rank to each row, Dense Rank assigns consecutive rank without gaps

• Example: Rank - 1, 2, 3, 4, 4, Dense Rank - 1, 2, 3, 4, 4

Different filters in Tableau include dimension filters, measure filters, top N filters, wildcard filters, and context filters.

• Dimension filters allow users to filter data based on categorical variables.

• Measure filters allow users to filter data based on numerical variables.

• Top N filters allow users to filter data based on the top or bottom N values.

• Wildcard filters allow users to filter data based on patterns or partial matches.

• Context filters allow users to create a temporar...read more

Data visualization is the graphical representation of data to help understand patterns, trends, and insights.

• Data visualization uses charts, graphs, and maps to present data visually.

• It helps in identifying patterns, correlations, and outliers in data.

• Examples include bar charts, line graphs, scatter plots, and heat maps.

Context filter is a filter applied to a specific visualization or worksheet, affecting the data displayed in that context.

• Context filters are used to limit the data displayed in a specific visualization or worksheet.

• They allow users to focus on specific subsets of data without affecting the overall data in the workbook.

• Context filters can be created based on dimensions or measures.

• They can be used to filter data based on specific conditions or criteria.

• Context filters can be ...read more

Auto refresh can be scheduled using Tableau Server or Tableau Online

• In Tableau Server, go to the dashboard and click on 'Schedule Refresh'

• Set the frequency and time for the refresh

• In Tableau Online, go to the dashboard and click on 'Schedule Refresh'

• Set the frequency and time for the refresh

• Make sure the data source is set to refresh before the dashboard refreshes

Sets are used for creating custom fields based on conditions, while groups are used for combining related fields together.

• Sets are dynamic and can change based on filters, while groups are static and do not change.

• Sets can be used for creating calculated fields, while groups are used for organizing fields.

• Example: Creating a set for 'High Sales' based on sales amount, and grouping 'Region' and 'City' fields together.

Tableau is more user-friendly and has better visualization capabilities than QlikView.

• Tableau has a more intuitive drag-and-drop interface

• Tableau has a wider range of visualization options

• Tableau has better integration with other data sources

• QlikView has better data modeling capabilities

• QlikView has better performance with large datasets

Tableau offers a variety of chart types to visualize data effectively.

• Bar chart - used to compare different categories

• Line chart - shows trends over time

• Pie chart - displays parts of a whole

• Scatter plot - shows relationships between two variables

• Heat map - visualizes data using color intensity

• Tree map - displays hierarchical data using nested rectangles

To calculate %YoY growth, subtract the previous year's value from the current year's value, divide by the previous year's value, and multiply by 100.

• Calculate YoY growth = ((Current Year Value - Previous Year Value) / Previous Year Value) * 100

• For example, if sales were $100 in 2020 and $120 in 2021, YoY growth = (($120 - $100) / $100) * 100 = 20%

Tableau dashboards are interactive visualizations that help users analyze and understand data.

• Dashboards are made up of multiple worksheets and can include filters, parameters, and actions.

• They allow users to explore data and answer questions in real-time.

• Dashboards can be shared with others and embedded in websites or other applications.

• Examples of dashboards include sales performance dashboards, marketing campaign dashboards, and financial analysis dashboards.

Filters and parameters are Tableau features used to refine data and customize visualizations.

• Filters are used to limit the data displayed in a visualization based on certain criteria.

• Parameters allow users to adjust certain aspects of a visualization, such as date ranges or color schemes.

• Both filters and parameters can be used to create interactive dashboards and improve data analysis.

• Examples of filters include date filters, categorical filters, and top N filters.

• Examples of...read more

To add custom SQL query in Tableau, go to Data menu, select New Data Source, choose your data connection, and then select Custom SQL option.

• Go to Data menu in Tableau

• Select New Data Source

• Choose your data connection

• Select Custom SQL option

• Enter your custom SQL query

To create dashboards and actions in Tableau, you can use the drag-and-drop interface to add visualizations and set up interactivity.

• Use the drag-and-drop interface to add visualizations to the dashboard

• Set up actions to create interactivity between different visualizations

• Define filter actions to allow users to interact with the data dynamically

To publish on Tableau Server, use Tableau Desktop to create a workbook, then save it to Tableau Server.

• Create a workbook in Tableau Desktop with the desired visualizations and data connections

• Save the workbook to Tableau Server by selecting 'Server' > 'Publish Workbook'

• Choose the project and permissions for the workbook on Tableau Server

• Access the published workbook on Tableau Server through a web browser or Tableau Desktop

Relationships define how tables are connected, blending combines data from different sources, and joins combine data from different tables.

• Relationships are used to connect tables based on common fields.

• Blending is used to combine data from different sources, such as Excel and SQL.

• Joins are used to combine data from different tables based on common fields.

• Blending is useful when the data sources have different levels of detail.

• Joins can be inner, left, right, or full dependin...read more

I have used Tableau versions 10.0, 10.1, 10.2, and 2018.1.

• Tableau 10.0

• Tableau 10.1

• Tableau 10.2

• Tableau 2018.1

Heat map displays data using color intensity while tree map displays data using nested rectangles.

• Heat map is used to show the distribution of data across a two-dimensional space.

• Tree map is used to display hierarchical data using nested rectangles.

• Heat map uses color intensity to represent the data values while tree map uses the size of the rectangles.

• Heat map is useful for identifying patterns and trends in large datasets while tree map is useful for visualizing hierarchica...read more

Optimizing Tableau dashboard involves simplifying visuals, reducing clutter, optimizing data sources, and utilizing performance tuning techniques.

• Simplify visuals by removing unnecessary elements and focusing on key metrics

• Reduce clutter by organizing data in a logical manner and using filters effectively

• Optimize data sources by cleaning and aggregating data before connecting to Tableau

• Utilize performance tuning techniques such as extracting data, using data blending instead ...read more

Type of Filter refers to the different ways in which data can be filtered in Tableau.

• Tableau offers various types of filters such as Quick Filters, Context Filters, Dimension Filters, Measure Filters, and Top/Bottom Filters.

• Quick Filters allow users to filter data by selecting values from a list.

• Context Filters create a temporary table that can be used to filter data more efficiently.

• Dimension Filters filter data based on the values of a particular dimension.

• Measure Filters f...read more

LOD stands for Level of Detail and is used to control the granularity of data in Tableau visualizations.

• LOD expressions allow users to compute values at different levels of granularity than the view

• Use cases include comparing sales performance at different levels of detail, such as by region or product category

• Another use case is calculating running totals or averages across different dimensions

I am responsible for managing Tableau Server, including user access, data sources, and performance optimization.

• Manage user access and permissions on Tableau Server

• Maintain data sources and ensure they are up-to-date

• Optimize server performance for faster loading times

• Troubleshoot any server-related issues

• Monitor server usage and performance metrics

A context filter is a filter that is applied to a specific worksheet or dashboard, affecting only the data displayed in that context.

• Context filters are used to filter data at a more granular level within a worksheet or dashboard.

• They allow users to focus on specific data points without affecting the overall data set.

• Context filters can be created by right-clicking on a field in the Filters shelf and selecting 'Add to Context'.

• Examples: Filtering sales data by region on a spe...read more

Groups and sets are two ways to organize and analyze data in Tableau.

• Groups are a way to combine related dimensions into a single category.

• Sets are a way to create a subset of data based on a condition or criteria.

• Groups can be created manually or by selecting related dimensions.

• Sets can be created based on a range of values, a condition, or a top/bottom percentage.

• Groups and sets can be used in calculations, filters, and visualizations.

Sets are custom fields that define a subset of data based on some conditions, while groups are a way of combining related dimensions into a single field.

• Sets are dynamic and can change based on filters, while groups are static and do not change.

• Sets can be used for creating calculated fields, while groups cannot.

• Sets can be used to highlight specific data points, while groups cannot.

• Examples of sets include top N sets, combined sets, and parameter sets, while examples of grou...read more

Pivot and Recursive CTE are advanced SQL techniques used for data transformation and hierarchical querying.

• Pivot is used to convert rows into columns based on a specific column value.

• Recursive CTE is used to query hierarchical data, such as organizational structures or bill of materials.

• Example of Pivot: SELECT * FROM table_name PIVOT (SUM(value) FOR column_name IN (value1, value2, value3))

• Example of Recursive CTE: WITH RECURSIVE cte AS (SELECT * FROM table_name UNION ALL SEL...read more

Creating dashboards involves selecting relevant data, designing visualizations, and arranging them in a user-friendly layout.

• Identify key metrics and data sources to include in the dashboard

• Design appropriate visualizations such as bar charts, line graphs, and maps

• Arrange visualizations in a logical and intuitive layout

• Use filters and parameters to allow users to interact with the data

• Add annotations and titles to provide context and insights

Level of Detail expressions are used to aggregate data at different levels of granularity within a visualization.

• LOD expressions allow for more granular control over aggregations

• They can be used to aggregate data at different levels of detail within a visualization

• Syntax includes curly braces and the keywords FIXED, INCLUDE, and EXCLUDE

• Examples include calculating sales by region and product category, or finding the average sales per customer

Tableau is a data visualization tool that helps in analyzing and presenting data in an interactive and meaningful way.

• Tableau allows users to create interactive dashboards and reports

• It can connect to various data sources and perform data blending

• Tableau provides advanced analytics capabilities like forecasting and trend analysis

• It helps in identifying patterns and trends in data that might not be visible otherwise

• Tableau is user-friendly and requires minimal coding knowledge

Types of LOD in Tableau include Fixed, Include, and Exclude.

• Fixed LOD: Computes a value using a specific dimension without reference to the view level

• Include LOD: Computes a value at a specified dimension level

• Exclude LOD: Computes a value at a specified dimension level excluding the dimension specified

Create a flag to identify data that has not been updated

• Add a new column in the dataset called 'Updated Flag'

• Use a formula to check if the data has been updated recently

• For example, if the last update date is more than 30 days ago, set the flag to 'Not Updated'

Live connection allows real-time data updates while extract connection improves performance by storing data locally.

• Live connection connects directly to the data source for real-time updates.

• Extract connection stores a snapshot of the data locally for faster performance.

• Live connection is suitable for small datasets or when real-time updates are crucial.

• Extract connection is recommended for large datasets or when performance is a priority.

Types of LODs in Tableau include Fixed, Include, and Exclude.

• Fixed LOD: Computes a value using specified dimensions, regardless of the visualization level.

• Include LOD: Computes a value at a specified level of detail, including dimensions not in the visualization.

• Exclude LOD: Computes a value at a specified level of detail, excluding dimensions not in the visualization.

Types of filters used in Tableau include extract filters, context filters, data source filters, and quick filters.

• Extract filters are used to filter data before it is extracted into Tableau.

• Context filters are used to filter data in a specific order, affecting subsequent filters.

• Data source filters are applied at the data source level, affecting all workbooks and views using that data source.

• Quick filters allow users to interactively filter data in a visualization.

Order of execution in Tableau determines the sequence in which calculations are performed.

• Filters are applied first

• Then calculations are performed

• Aggregations are computed next

• Table calculations are executed last

Joins are used to combine data from different tables based on a related column, while blending is used to combine data from different data sources within the same worksheet.

• Joins are used when you have related data in different tables and want to combine them based on a common column.

• Blending is used when you have data from different sources like Excel and SQL and want to combine them in the same worksheet.

• Joins require a common key to match the data, while blending does not ...read more