Tableau Interview Question and Answer

Part 1:

1) What is Tableau?

Tableau is a powerful data visualization tool used in the Business Intelligence Industry. It helps in simplifying raw data into a very easily understandable format.

2) What are the popular features of Tableau?

The popular features of Tableau are:

• Data blending
• No need of technical knowledge
• Real-time analysis
• Data collaboration and data notifications
• DAX analysis function
• Patented technology from Stanford university
• Toggle view and drag-and-drop
• List of native data connectors
• Highlight and filter data
• Share dashboards
• Embed dashboards within
• Mobile-ready dashboards
• Tableau reader for data viewing
• Dashboard commenting
• Create “no-code” data queries
• Translate queries to visualizations
• Import all ranges and sizes of data

3) What is Tableau Public?

Tableau Public is a free service that allows anyone to publish interactive data to the web. Once it is on the web, anyone can interact with the data, download it, or create their own data visualization.

4) What are the properties of Tableau combined sets?

Properties of Tableau combined sets are:

• Name: It is used to specify the unique name of a tableau set.
• Sets: Users can select the existing set from the menu. The first set in the menu acts as a left set. The second set act as the right set.
• All members in both sets: This is an option to combined set that holds all the members from left as well as right set.
• Shared members in both sets: This option holds matching members from both left and right sets. It means every record must match the condition present in these sets.
• Left set except shared members: This Tableau set is used to hold all the members from the left set except matching members from the righsst set.
• Right set except shared members: It holds all the members from the right set by matching members from the left set.

5) What are the different Tableau files?

Different Tableau files include:

• Workbooks: Workbooks hold one or more worksheets and dashboards.
• Bookmarks: It contains a single spreadsheet, and it’s an easy way to quickly share your work.
• Packaged workbooks:It includes a workbook having supporting background images and local file data.
• Data extraction files: Data extract files are basically a local copy of the entire data source or a subset.
• Data connection files: It is a XML file containing various information related to connection.

6) What is the basic difference between published data sources and embedded data sources in Tableau

The basic difference between a published data source and an embedded data source is:

The public data source contains connection information that is independent of any workbook. On the other hand, embedded data source connection information and is associated with a workbook.

7) Mention the characteristics that distinguish data source

The characteristics that distinguish data source are:

• Icon/Name
• Connection Type
• Connects to
• Live or the last extract

8) What are Joins?

Tableau can “join” tables. It can join up to 32 tablets in a data source. Two or more tables can be specified while joining the relationship. The tables present in the data source can be related to each other using the joins such as inner join, left join, right join, and outer join.

9) Explain Tableau Data Extract

A Tableau data extract is a compressed snapshot of data stored on disk. It is loaded into memory to render a Tableau.

10) Explain the primary differences between blending and joining in Tableau?

Joining terms is helpful when you are combining data from the same source. On the other hand, blending would require two completely defined data sources in your report.

11) How many maximum numbers of tables can be joined in Tableau?

The maximum number of tables that can be joined in Tableau is 32.

12) Name the different type of Tableau

The other kind of Tableau products are:

• Desktop
• Prep
• Online
• Server

 13) Explain Longitude and Latitude in tableau

Longitude and Latitude (generated) fields are associated with the geographical detail present in the data. The dataset should consist of geographic information like City, Country, or State.

The longitude and latitude values are auto-generated in Tableau. These fields can be used to build maps in Tableau.

14) Why use a hierarchical field in tableau?

A hierarchical field in tableau helps you to drill down data. It allows you to view your data in a more granular level.

15) Explain Connect live

Connect live creates a direct connection to the data source and speed up access.

16) Define the term analytics pane concerning Tableau

The analytics pane offers quick and easy access to everyday analytic objects in Tableau. It allows you to drag forecasts, reference and trend lines, and other objects into your view from the Analytics pane.

17) Explain the term filter actions

Filter actions show related information between a source sheet and one or more target sheets. This type of activities best suited when a developer is building a guided logical path using a workbook or in a dashboard.

18) How to view SQL generated by Tableau Desktop?

A developer can click on My Tableau Repository folder available in My documents in PC to view SQL. If the user is using a live connection to the data source, then check tabprotosrv.txt and log.txt files. If the user is using extract, check the tdeserver.txt file. This file shows details about queries.

19) List out Three Tableau limitation

Here are some notable limitations in Tableau:

• The parameter doesn’t accept multiple sections.
• User can’t define the width and columns individually.
• Users can’t control the selection, display, sorting of columns in view data option for a worksheet view.

20) How can you perform load testing in Tableau?

Users can do load testing with the help of Tableau Server performance testing solution called TabJolt. However, this is third-party software that is not supported by tableau directly. Therefore, it may be installed using other open-source products.

21) Where can a developer use global filters?

A developer can use global filters in sheets, dashboards, and stories.

22) What is a parameter in Tableau?

Parameters in Tableau are dynamic values that you can replace as constant values in calculations. These values serve as context filters.

23) What is the use of showing me in Tableau?

The show me clause is used to applying a required view to existing data in the worksheet. Views are displayed in graphical formats like a line chart, pie chart, and scatter plot.

24) How to get the current date and time in Tableau?

A developer can get the current date and time in Tableau using the NOW() function.

25) What is Forecasting in Tableau?

Forecasting means predicting the future value of a measure. There are various methods for forecasting. However, in Tableau, the user can only use exponential smoothing.

26) What is the calculated field in Tableau?

A calculated field is a new field that you can create using a formula to modify the existing filed in your data source.

27)  What is the use of formatting pane in Tableau

A formatting pane contains a setting that controls the entire worksheet and individual fields in

28) Explain Tableau Product Suite

The Tableau Product Suite consists of

• Tableau Desktop
• Tableau Public
• Tableau Online
• Tableau Server
• Tableau Reader

For a clear understanding, data analytics in the tableau can be classified into two section

Tableau Desktop

Tableau Desktop has a rich feature set and allows you to code and customize reports. It ables users to create charts, reports, and dashboards.

Tableau Public

It is the Tableau version specially build for cost-effective users. By the word “Public,” it means that the workbooks created cannot be saved locally. In turn, it should be saved to Tableau’s public cloud, which can be viewed and accessed by anyone.

Tableau Server

The software is specifically used to share the workbooks, visualizations that are created in the Tableau Desktop application across the organization.

Tableau Online

As the name suggests, it is an online sharing tool for Tableau. Its functionalities are similar to Tableau Server, but the data is stored on servers hosted in the cloud, which are maintained by the Tableau group.

Tableau Reader

Tableau Reader is a free tool that enables the user to view the workbooks and visualizations created using Tableau Desktop or Tableau Public. The data can be filtered, but editing and modifications are restricted. The security level is zero in Tableau Reader as anyone who gets the workbook can view it using Tableau Reader.

29) Differentiate between Excel and Tableau?

The difference between Excel and Tableau is:

30) Explain the classification of tableau

Tableau is classified into two sections:

• Developer Tools: The Tableau tools that are used for development, such as the creation of dashboards, charts, report generation, visualization, fall into this category. Tableau products, under this category, are the Tableau Desktop and Tableau Public.
• Sharing Tools: As the name suggests, the purpose of the tool is to share the visualizations, reports, dashboards that were created using the developer tools. Products that fall into this category are Tableau Online, Server, and Reader.

31) What is the difference between Traditional BI Tools and Tableau?

The difference between Traditional BI Tools and Tableau is:

32) List the various datatypes in Tableau?

Various data types in the tableau are: 1) Boolean, 2) date, 3) date and time, 4) geographical values, and 5) text/string, number.

33) Explain Tableau Desktop Professional

Tableau Desktop Professional is pretty much similar to Tableau Desktop. The difference is that the work created in the Tableau Desktop can be published online or in Tableau Server. The professional version provides full access to all sorts of the datatype. It is best suitable for those who wish to publish their work in Tableau Server.

33) What are the dimensions?

Dimensions are the values of attributes used for multiple dimensions. It has a reference of a product key form the table. It can contain product name, color, size, product type, description, etc.

34) What is a group?

A group is a collection of dimension members which can make categories of higher level.

35) What is the key difference between .twb and .twbx extension?

Twb is a one of the XML document that contains all the layouts and selections made by the user whereas Twbx is a ‘zipped’ archive which contains .twb and external files like background images and extracts.

36) What is Set?

Set is a custom filed that defines a data subset based on some computed condition or data point.

37) Explain various types of Joins in tableau

Various types of Joins in Tableau are:

Inner Join:

It joins all the common records between two tables or sheets. The joining condition can be given based on the primary key. One or more joining conditions can be specified to join the tables. Many tables can be joined together in Tableau for visualization.

Left Join:

A left join is used to join all the records from a left table and common records from the right table. One or more join conditions can be specified to left join two different tables.

Right Join:

A right join is used to join all the records from the right table and common records from the left table. Based on the requirements, one or more joining conditions can be set.

Outer Join:

An Outer join is used to join all the records from both the left and right table. Joining conditions can be set to join common records.

38) Explain the context filter

A Context filter is an independent filter that can create a separate dataset out of the original data set and compute the selections made in the worksheet. One or more categorical filter that separates the dataset into major parts can be used as a context filter. All other filters used in the worksheet works based on the selection of context filter. The functions of context filters can be explained through an excel sheet.

39) What is Dimension Filters?

When a dimension is used to filter the data in a worksheet, it is called a Dimension filter. It is a non-aggregated filter where a dimension, group, sets, and the bin can be added. A dimension filter can be applied through the top or bottom conditions, wildcard match, and formula.

40) What is Dimension Filters?

A measure filter can filter the data based on the values present in a measure. The aggregated measure values can be used in measure filters to modify the data.

41) What are the advantages of Using Context Filters?

The advantages of Using Context Filters

• Improve Performance: When context filter is used in large data sources, it can improve the performance as it creates a temporary dataset part based on the context filter selection. The performance can be effectively improved through the selection of major categorical context filters.
• Dependent Filter Conditions: Context filters can be used to create dependent filter conditions based on the business requirement. When the data source size is large, context filters can be selected on the primary category, and other relevant filters can be executed.

42) Mention the primary difference between joining and blending in Tableau

Joining is a term that is used when the user combines data from the same source like tables in oracle or excel file while Blending needs two completely defined data sources report

43) Name the components of a Dashboard

Important components of a Dashboard are:

• Horizontal: A horizontal layout allows the designer to group dashboard components and worksheets across the page.
• Vertical: Vertical containers enables the user to group dashboard components and worksheets top to bottom down your page. It also allows users to edit the width of all elements at once.
• Text: It contains all textual files
• Image Extract: Tableau applies some code to extract the image that is stored in XML.
• URL action: It is a hyperlink that points to file, web page, or other web-based resources.

44) Explain story in Tableau

A story is a sheet containing a dashboard or worksheet sequence that works together to convey particular information.

45) Explain Tableau drive

Tableau drive is one methodology that can be used for scaling out analytics. It is based on best practices from successful deployments of an enterprise.

46) Explain the Tableau architecture

Different components of Tableau architecture are:

Data server: The primary component of Tableau Architecture is the Data sources it can connect to it.

Data Connectors: The Data Connectors provide an interface to connect external data sources to the Tableau Data Server.

Components of Tableau Server:

1) Application Server:

The application server is used to provide the authentications and authorizations. It handles the administration and permission for web and mobile interfaces.

2) VizQL Server:

VizQL server is used to convert the queries from the data source into visualizations. Once the client request is forwarded to VizQL process, it sends the query directly to the data source and retrieves information in the form of images.

3) Gateway:

The gateway channelizes the requests from users to Tableau components. When the client makes a request, it is forwarded to the external load balancer for processing. The gateway works as a distributor of processes to various components.

4) Clients:

The dashboards and visualizations in Tableau server can be viewed and edited using different clients. The Clients are Tableau Desktop, web browser, and mobile applications.

47) Explain Measure filter

A measure filter can filter the data based on the values present in a measure. The aggregated values can be used in measure filters to modify the data.

48) Distinguish between Treemaps and Heat Maps

The difference between Treemaps and Heat Maps are:

49) What is the use of toolbar Icon?

Toolbar icon present below the menu bar can be used to edit the workbook using different features such as undo, redo, save, new data source, slideshow, and so on.

50) What is the use of a blended axis?

Blended axis is used to blend measures that share the axis when they have the same scale.

51) What is the use of dual-axis?

Dual Axis enables users to compare measures. It is useful when they like to compare two measures having different scales.

52) What is LOD expression?

A LOD or (Level of Detail) expression is used to run complicated queries that involve many dimensions at the data source level.

53) Explain data modeling

Data modeling (data modeling) is the process of creating a data model for the data to be stored in a database.

This data model is a conceptual representation of Data objects, the associations between different data objects, and the rules. Data modeling helps in the visual representation of data and enforces business rules, regulatory compliances, and government policies on the data.

54) Explain stacked bar chart

Stacked Bar Chart is a chart that is composed of more than one bar that is stacked horizontally. The length of the bar is depended on the value given in the data point. This type of chart makes work more comfortable and helps the user to know changes in all the variables. Users can match the wanted changes in their future values.

55) Explain Page shelf

Page shelf can be used to view the visualization in video format by keeping the relevant filter on the page shelf.

56)  Explain filter shelf

The filters that can control the visualization can be placed on the filter shelf, and the required dimensions or measures can be filtered in.

57) Define a bullet graph

A bullet graph is a modification of a bar graph. It is responsible for comparing the performance of measures.

58) Explain bar chart in Tableau

A bar chart can compare the data across different categories. The height of the bars represents the measured value of each category. It can be represented as vertical and horizontal type bar charts.

59) Explain VIZQL in Tableau

VIZQL stands for Visual Inquiry Language. It is a combination of SQL and VIZ. Visual query languages are similar to the SQL language. This language converts queries of data into visual images.

60) Mention various types of functions commonly used in Tableau

Various types of functions commonly used in the tableau are:

• String functions: It includes LEFT, LOWER, LTRIM, MID, and more.
• Logical functions: This function contains and, else, else if, if, ifnull, isdate, isnull, max, min, etc.
• Aggregate functions: It includes attr, collect, count, covar, and covarp.
• User functions: User define functions contain full name, is the full name, is member of, username, username, user domains, etc.

61) What is Line Chart?

A-Line Chart is used to compare the data over different periods. A line chart is created by a series of dots. These dots represent the measured value in each period. The procedure to create a line graph is shown below.

62) List the categories of dimensions in Tableau

The categories of dimensions in Tableau are:

• Slowly ever
• Chop-chop ever
• Unchanged dimension
• Shrunken dimension
• Junk dimension
• Conformed dimension
• Degenerated dimension
• Role enjoying dimension
• Inferred dimension

63) What are the various ways to use parameters in Tableau?

Various ways to use parameters in Tableau are: 1) filters, 2) calculated fields, 3) actions, 4) measure-swaps, 5) changing views, and 6) auto-updates

64) What is the user filter?

User filter secures the row-level data present in a dataset. It can be used when publishing the workbook on a server. Different filter conditions can be applied to different users.

65) Define Histogram chart

A histogram can show the values present in a measure and its frequency. It shows the distribution of numerical data. As it shows both frequency and measure value by default, it can be useful in many cases.

66) What are the user functions in Tableau?

The user functions in Tableau are unique functions that Tableau developers can use to perform operations on the registered users on Tableau Online or Tableau Server.

67) Explain paged workbook

A paged workbook in Tableau consists of different pages based on specific criteria.

68) Define shelves in Tableau

The Shelves in Tableau are demarcated areas that are used for particular purposes. There are several shelves on a Tableau sheet-like, Filter shelf, Page shelf, Rows and Column shelf, Marks shelf, etc.

69) Explain bin

Bin is a user-defined set of data that are of the equal interval that stores data values according to or which fits in bin size.

70) Explain bubble Chart

A bubble chart visualizes the measures and dimensions in the form of bubbles. The sizes of the bubbles determine the size of the measured value for effective visualization. The color of bubbles can be set to differentiate the members present in a dimension.

71) Define Hyper

Hyper is a high-performance in-memory information engine innovation. It allows clients to analyze complex or large informational sets speedier. This can be done by proficiently assessing analytically questions which are in the value-based database.

72) What are the combined Sets?

The combined Sets in Tableau are handy to compare two existing sets for further analysis.

73) What is Backgrounder?

The backgrounder refreshes planned extracts, conveys notifications, and handle other assignments run in the background. The backgrounder is responsible for expending as much as the processor is accessible to finish the background action as fast as possible.

74) Explain data visualization

Data visualization is one of the forms of visual communication. It includes producing images that communicate relationships among the data. This process can be achieved using a systematic mapping between data values and graphic marks.

75) How to perform performance testing in Tableau?

User can perform performance testing in Tableau using by:

• Recording performance information about the events that interact with the workbook.
• Reviewing the tableau desktop logs.

76) What is Aggregation?

Aggregation is the process of viewing measures or numeric values at higher and more summarized data.

78) Why use Disaggregation in Tableau?

Disaggregation is a Tableau used to view every row of the data source. It is useful while analyzing measures for both independent and dependent data in the view.

79) What the limitations of setting channels

The limitations of setting channels are:

• If the channel is changed by the customers on a regular basis, the database should be reprocessed and modify the short-lived table.
• The transient table needs to reload every time when the view is begun.

80) What is the difference between Tableau and QlikView?

The difference between Tableau and QlikView is:

81) What is the Tableau data engine?

Tableau data engine manages to open, refresh, create, and query extracts of the user.

82) What is metadata in Tableau?

Metadata in tableaus refers to the editing of original data in Tableau. It includes custom data and formatting of data.

83) Explain dashboard lifecycle

Dashboard lifecycle in Tableau:

Functional Knowledge: Business Analysts give a current functional knowledge of the organization.

Requirement Analysis: Requirements that are kept in consideration are:

• The requirement of the dashboard.
• How is data flowing in the current system?
• Blueprint or layout of the system.
• Dashboard scope.
• The value that is added to the business
• Required tools for the development of the project and its costs.

Planning Phase: It includes:

• Timeline and needed resources.
• Work and leave plan.
• Dependencies and future challenges.

Methodologies to follow: Scrum, Agile, Waterfall, etc.

Technical Specs: It includes:

• Technical details.
• SQL, relations, and Joins.
• Credentials for database access.
• Business logic.

Development: It includes:

• Query generation.
• Connecting databases and creating dimension model
• Publish it to the server.
• Unit testing.

Q&A Testing: It includes:

• Functionality and UI testing.
• SQL testing and data validation
• Security testing
• Testing of applied customization.

Performance testing: Report opening time, with or without any webpage.

User Acceptance Testing (UAT): User validates data and functionality.

Production and Support: System is produced, and support is given once it goes live.

84) What are the advantages of Tableau over excel?

The advantages of Tableau over excel are:

• Tableau handles big data problems.
• Excel does not have large columns and rows.
• Excel has lesser resources than tableau.

85) What is the use of marks cards?

Marks cards can be used to design the visualization. The data components of the visualization, like color, size, shape, path, etc. used in the visualizations. It can be modified in the marks card.

86) List the types of maps available in Tableau

There are six types of maps in Tableau:

• Choropleth maps (filled maps)
• Proportional symbol maps
• Spider maps (origin-destination maps)
• Heatmaps (density maps)
• What are Discrete data in tableau
• Point distribution maps
• Flow maps (path maps)

87) What is the use of a custom data view?

A custom data view is used by tableau users to extend the normal data views to gain the advantage of additional features.

88) What is Tableau Table Report?

Table Report in Tableau provides the primary ways to display data in tabular format.

89) What are the types of data sources that can be connected to Tableau’s native connectors?

What are the types of data sources that can be connected to Tableau’s native connectors are:

• File systems like Excel and CSV.
• Relational systems like SQL Server, Oracle, DB2, etc.
• Cloud systems like Google BigQuery and Microsoft Azure.
• Database connection sources such as ODBC.

90) What is the use of data blending?

Data blending is used when the is a possibility of related data in multiple sources that you need to analyze in a view.

91) What is Worksheet in Tableau?

The worksheet is the place where the actual visualization can be viewed in the workbook. The design and functionalities of the visual can be viewed in the worksheet.

92) What is the data source page?

The data source page is a page where users can set up their sources of data. It generally contains four main areas: 1) left pane, 2) join area, 3) preview area, and 4) metadata area.

93) What is format pane?

A pane that contains formatting settings to control the worksheet and fields available in the view is called format pane. It appears on the left side of the tableau workbook.

94) Explain Tableau Navigation

The navigation of workbook contains:

• Data Source: The addition of a new data source of modification of existing data sources can be done using the ‘Data Source’ tab present at the bottom of the Tableau Desktop Window.
• Current Sheet: Current Sheet can be viewed with the name of the sheet. All the sheets, dashboards, and storyboard present in the workbook can be viewed here.
• New Sheet: The new sheet icon present in the tab can be used to create a new worksheet in the Tableau Workbook.
• New Dashboard: The new dashboard icon present in the tab can be used to create a new dashboard in the Tableau Workbook.
• New Storyboard: The new storyboard icon present in the tab can be used to create a new storyboard in the Tableau Workbook.

95) What are the types of Level of Detail?

There are three main types of LOD expressions.

• Fixed LOD: It is a LOD expression that computes values using the mention dimensions without reference to any dimensions.
• Include LOD: This expression compute values using the mention dimensions along with those who are present in view.
• Exclude LOD: These LOC expressions subtract dimensions from the view.

96) What are the ways to sort out data in Tableau?

The ways to sort out data in Tableau are:

Computed sorting: It is a sort that can be applied on an axis using a sort button.

Manual sorting: It can be used to rearrange the dimension field order by dragging them to each other in an ad hoc manner.

97) What is the data server?

The data server is used to manage and store the data from external data sources. It is a central data management system. It provides metadata management, data security, data storage, data connection, and driver requirements. It stores the relevant details of data set such as metadata, calculated fields, sets, groups, and parameters. The data source could extract data as well as make live connections to external data sources.

98) What is the use of trend lines?

Trend lines are used to know the continuation of a trend of variables. It helps users to search the correlation between two or more variables. There is a wide range of mathematical models for establishing trend lines. These models are 1) Logarithmic, 2) Linear, 3) Exponential, and 4 ) Polynomial.

99) Explain alias in Tableau

Alias in Tableau can refer as an alternative name that the user can assign to a dimension member a field.

100) What are Data Labels in Tableau Reports?

Data Labels in Tableau reports or any other Business Intelligence reports play a vital role in understanding the report data.

101) What is Tableau Crosstab Report?

Table Crosstab in Tableau is the best way to display data in multi-level.

102) What is the waterfall Chart?

Waterfall Chart can visualize the cumulative effect of a measure over dimension. It can show the contribution of growth or decline by each member in a dimension. For example, you can see the contribution of profit by each sub-category using a waterfall chart.

103) Explain measure names

Measure names and Measure values are the two fields created in Tableau by default. These fields are created when a data set is imported into Tableau.

Part 2:

1. What is data visualization in Tableau?

Data visualization is a way to represent data that is visually appealing and interactive. With advancements in technology, the number of business intelligence tools has increased which helps users understand data, data sets, data points, charts, graphs, and focus on its impact rather than understanding the tool itself.

2. What is the difference between various BI tools and Tableau?

The basic difference between the traditional BI tools and Tableau lies in the efficiency and speed.

• The architecture of Traditional BI tools has hardware limitations. While Tableau does not have any sort of dependencies
• The traditional BI tools work on complex technologies while Tableau uses simple associative search to make it dynamic. 
• Traditional BI tools do not support multi-thread, in-memory, or multi-core computing while Tableau supports all these features after integrating complex technologies. 
• Traditional BI tools have a pre-defined data view while Tableau does a predictive analysis for business operations.

3. What are different Tableau products?

Tableau like other BI tools has a range of products:

• Tableau Desktop:Desktop product is used to create optimized queries out from pictures of data. Once the queries are ready, you can perform those queries without the need to code. Tableau desktop encompasses data from various sources into its data engine and creates an interactive dashboard. 
• Tableau Server:When you have published dashboards using Tableau Desktop, Tableau servers help in sharing them throughout the organization. It is an enterprise-level feature that is installed on a Windows or Linux server. 
• Tableau Reader:Tableau Reader is a free feature available on Desktop that lets you open and views data visualizations. You can filter or drill down the data but restricts editing any formulas or performing any kind of actions on it. It is also used to extract connection files. 
• Tableau Online:Tableau online is also a paid feature but doesn’t need exclusive installation. It comes with the software and is used to share the published dashboards anywhere and everywhere. 
• Tableau Public:Tableau public is yet another free feature to view your data visualizations by saving them as worksheets or workbooks on Tableau Server.

4. What is a parameter in Tableau?

The parameter is a variable (numbers, strings, or date) created to replace a constant value in calculations, filters, or reference lines. For example, you create a field that returns true if the sales are greater than 30,000 and false if otherwise. Parameters are used to replace these numbers (30000 in this case) to dynamically set this during calculations. Parameters allow you to dynamically modify values in a calculation. The parameters can accept values in the following options:

• All:Simple text field
• List:List of possible values to select from
• Range:Select values from a specified range

5. Tell me something about measures and dimensions?

In Tableau, when we connect to a new data source, each field in the data source is either mapped as measures or dimensions. These fields are the columns defined in the data source. Each field is assigned a datatype (integer, string, etc.) and a role (discrete dimension or continuous measure).

Measures contain numeric values that are analyzed by a dimension table. Measures are stored in a table that allows storage of multiple records and contains foreign keys referring uniquely to the associated dimension tables.

While Dimensions contain qualitative values (name, dates, geographical data) to define comprehensive attributes to categorize, segment, and reveal the data details.

6. What are continuous and discrete field types?

Tableau’s specialty lies in displaying data differently either in continuous format or discrete. Both of them are mathematical terms used to define data where continuous means without interruptions and discrete means are individually separate and distinct.

While the blue color indicates discrete behavior, the green color indicates continuous behavior. On one hand, the discrete view defines the headers and can be easily sorted, while continuous defines the axis in a graph view and cannot be sorted.

7. What is aggregation and disaggregation of data?

Aggregation of data means displaying the measures and dimensions in an aggregated form. The aggregate functions available in the Tableau tool are:

• SUM (expression):Ads up all the values used in the expression. Used only for numeric values.
• AVG (expression):Calculates the average of all the values used in the expression. Used only for numeric values.
• Median (expression):Calculates the median of all the values across all the records used in the expression. Used only for numeric values.
• Count (expression):Returns the number of values in the set of expressions. Excludes null values.
• Count (distinct):Returns the number of unique values in the set of expressions.

Tableau, in fact, lets you alter the aggregation type for a view.

Disaggregation of data means displaying each and every data field separately.

8. What are the different types of joins in Tableau?

Tableau is pretty similar to SQL. Therefore, the types of joins in Tableau are similar:

• Left Outer Join:Extracts all the records from the left table and the matching rows from the right table.
• Right Outer Join:Extracts all the records from the right table and the matching rows from the left table.
• Full Outer Join:Extracts the records from both the left and right tables. All unmatched rows go with the NULL value. 
• Inner Join:Extracts the records from both tables.

9. Tell me the different connections to make with a dataset?

There are two types of data connections in Tableau:

LIVE: Live connection is a dynamic way to extract real-time data by directly connecting to the data source. Tableau directly creates queries against the database entries and retrieves the query results in a workbook.

EXTRACT: A snapshot of the data, extract the file (.tde or .hyper file) contains data from a relational database. The data is extracted from a static source of data like an Excel Spreadsheet. You can schedule to refresh the snapshots which are done using the Tableau server. This doesn’t need any connection with the database.

10. What are the supported file extensions in Tableau?

The supported file extensions used in Tableau Desktop are:

• Tableau Workbook (TWB): contains all worksheets, story points, dashboards, etc.
• Tableau Data Source (TDS):contains connection information and metadata about your data source
• Tableau Data Extract (TDE):contains data that has been extracted from other data sources.
• Tableau Packaged Workbook (TWBX):contains a combination of the workbook, connection data, and metadata, and the data itself in the form of TDE.  It can be zipped and shared.
• Tableau Packaged Data Source (TDSX):contains a combination of different files.
• Tableau Bookmark (TBM):to earmark a specific worksheet.

11. What are the supported data types in Tableau?

The following data types are supported in Tableau:

12. What are sets?

Sets are custom fields created as a subset of the data in your Tableau desktop. Sets can be computed based on conditions or created manually based on the dimensions of the data source. 
For example, A set of customers that earned revenue more than some value. Now, set data may update dynamically based on the conditions applied. 

13. What are groups in Tableau?

Groups are created to visualize larger memberships using dimensions. Groups can create their own fields to categorize values in that specific dimension.

14. What are shelves?

Tableau worksheets contain various named elements like columns, rows, marks, filters, pages, etc. which are called shelves. You can place fields on shelves to create visualizations, increase the level of detail, or add context to it.

15. Tell me something about Data blending in Tableau?

Data blending is viewing and analyzing data from multiple sources in one place. Primary and secondary are two types of data sources that are involved in data blending.

16. How do you generally perform load testing in Tableau?

Load testing in Tableau is done to understand the server’s capacity with respect to its environment, data, workload, and use. It is preferable to conduct load testing at least 3-4 times in a year because with every new user, upgrade, or content authoring, the usage, data, and workload change. 

Tabjolt was created by Tableau to conduct point-and-run load and performance testing specifically for Tableau servers. Tabjolt:

• Automates the process of user-specified loads
• Eliminates dependency on script development or script maintenance
• Scales linearly with an increase in the load by adding more nodes to the cluster

17. Why would someone not use Tableau?

The limitations of using Tableau are:

• Not cost-effective:Tableau is not that cost-effective when we compare it well with the other available data visualization tools. In addition to this, it has software upgrades, proper deployment, maintenance, and also training people for using the tool.
• Not so secure:When it comes to data, everyone is extra cautious. Tableau focussed on security issues but fails to provide centralized data-level security. It pushes for row-level security and creates an account for every user which makes it more prone to security glitches.
• BI capabilities are not enough:Tableau lacks basic BI capabilities like large-scale reporting, building data tables, or creating static layouts. It has limited result-sharing capabilities, email notification configuration is limited to admins, and the vendor doesn’t support trigger-based notifications.

18. What is Tableau data engine?

An analytical database that computes instant query responses, predictive analysis of the server, and integrated data. The data engine is useful when you need to create, refresh, or query extracts. It can be used for cross-database joins as well.

19. What are the various types of filters in Tableau?

Tableau has 6 different types of filters:

• Extract Filter:This filter retrieves a subset of data from the data source.
• Dimension Filter:This filter is for non-aggregated data (discrete).
• Data Source Filter:This filter refrains users from viewing sensitive information and thus reduces data feeds.
• Context Filter:This filter creates datasets by applying presets in Tableau.
• Measure Filter:This filter applies various operations like sum, median, avg, etc.
• Table Calculation Filter:This filter is applied after the view has been created.

20. What are dual axes?

Dual axes are used to analyze two different measures at two different scales in the same graph. This lets you compare multiple attributes on one graph with two independent axes layered one above the other.

To add a measure as a dual-axis, drag the field to the right side of the view and drop it when you see a black dashed line appear. You can also right-click (control-click on Mac) the measure on the Columns or Rows shelf and select Dual Axis.

21. What is the difference between a tree and heat map?

Both the maps help in analyzing data. While a heat map visualizes and compares different categories of data, a tree map displays a hierarchical structure of data in rectangles. Heat map visualizes measures against dimensions by depicting them in different colors. Similar to a text table with values defined in different colors.

Heat map in Tableau

Tree map visualizes the hierarchy of data in nested rectangles. Hierarchy levels are displayed from larger rectangles to smaller ones.

Example – Below tree map shows aggregated sales totals across a range of product categories:

TreeMap in Tableau

22. What are extracts and schedules in Tableau server?

Data extracts are the subsets of data created from data sources. Schedules are scheduled refreshes made on extracts after publishing the workbook. This keeps the data up-to-date. Schedules are strictly managed by the server administrators.

23. What are the components in a dashboard?

The components displayed in a dashboard are:

• Horizontal:Horizontal view allows the users to combine the worksheets and dashboard elements from left to right and edit the height of the elements.
• Vertical:Vertical view allows the users to combine the worksheets and dashboard elements from top to bottom and edit the width of the elements.
• Text:All the textual fields.
• Image Extract:To extract an image Tableau applies some code, extracts the image, and saves it in a workbook in the XML format.
• Web URL:Hyperlink that points to a web page, file, or other web resources outside of Tableau

24. What is a TDE file?

TDE is Tableau Desktop Extension with extension .tde. TDE file points to a file that contains data from external sources like MS Excel, MS Access, or CSV files. TDE makes it easier to analyze and discover data.

25. What is the story in Tableau?

Creating a story is effective in Tableau which is created by combining various charts to portray a plot of viewers. A story is a sheet that contains all the methods used to create those worksheets. To create a story:

1. Click the New Story on the dashboard.
2. Choose the right size of the story from the bottom-left corner or choose a custom size.
3. Start building the story by double-clicking the sheet and add it to the story point.
4. Add a caption to the story by clicking Add a caption.
5. You can update the highlights by clicking Update in the toolbar. You can also add layout options, format a story, or fit the story to your dashboard.
6. What are different Tableau files?

• Workbooks:Workbooks contain one or more worksheets and dashboard elements.
• Bookmarks:Contains a single worksheet that is easier to share.
• Packaged Workbooks:Contains a workbook along with supporting local file data and background images.
• Data Extraction Files:Extract files that contain a subset of data.
• Data Connection Files:Small XML file with various connection information.

27. How do you embed views into webpages?

You can easily integrate interactive views from your Tableau Server or Tableau online onto webpages, blogs, web applications, or internet portals. But to have a look at the views, the permissions demand the viewer to create an account on the Tableau Server. To embed views, click the Share button on the top of the view and copy the embed code to paste it on the web page.

You can also customize the embedded code or Tableau Javascript APIs to embed views.

28. What is the maximum no. of rows Tableau can utilize at one time?

The maximum number of rows or columns is indefinite because even though Tableau contains petabytes of data, it intelligently uses only those rows and columns which you need to extract for your purpose.

29. Mention what is the difference between published data sources and embedded data sources in Tableau?

Connection information is the details of data that you want to bring into Tableau. Before publishing it, you can create an extract of the same.

Published Data Source: It contains connection information that is independent of any workbook.

Embedded Data Source: It contains connection information which is connected to a workbook

30. What is the DRIVE Program Methodology?

DRIVE program methodology creates a structure around data analytics derived from enterprise deployments. The drive methodology is iterative in nature and includes agile methods that are faster and effective.

31. How to use groups in a calculated field?

Add the ‘GroupBy’ clause to SQL queries or create a calculated field in the data window to group fields.

• Using groups in a calculation. You cannot reference ad-hoc groups in a calculation.
• Blend data using groups created in the secondary data source: Only calculated groups can be used in data blending if the group was created in the secondary data source.
• Use a group in another workbook. You can easily replicate a group in another workbook by copy and pasting a calculation.

32. Explain when would you use Joins vs. Blending in Tableau?

While the two terms may sound similar, there is a difference in their meaning and use in Tableau:

While Join is used to combine two or more tables within the same data source.

Blending is used to combine data from multiple data sources such as Oracle, Excel, SQL server, etc.

33. What is Assume referential integrity?

In some cases, you can improve query performance by selecting the option to Assume Referential Integrity from the Data menu. When you use this option, Tableau will include the joined table in the query only if it is specifically referenced by fields in the view.

34. What is a Calculated Field, and How Will You Create One?

Calculated fields are created using formulas based on other fields. These fields do not exist but are created by you.

You can create these fields to:

• Segment data
• Convert the data type of a field, such as converting a string to a date.
• Aggregate data
• Filter results
• Calculate ratios

There are three main types of calculations that you can create:

• Basic Calculations: Transform values of the data fields at the source level
• Level of Detail (LOD) Expressions: Transform values of the data fields at the source level like basic calculations but with more granular access
• Table Calculations: Transform values of the data fields only at the visualization level

To create calculate fields:

In Tableau, navigate to Analysis>Create a calculated field. Input details in the calculation editor.
And, done!

35. How Can You Display the Top Five and Bottom Five Sales in the Same View?

You can see top five and bottom five sales with the help of these functions:

1. Drag ‘customer name’ to row and sales to the column.
2. Sort Sum (sales) in descending order.
3. Create a calculated field ‘Rank of Sales’.
4. What is the Rank Function in Tableau?

Rank function is used to give positions (rank) to any measure in the data set. Tableau can rank measure in the following ways:

• Rank: The rank function in Tableau accepts two arguments: aggregated measure and ranking order (optional) with a default value of desc.
• Rank_dense: The rank_dense also accepts the two arguments: aggregated measure and ranking order. This assigns the same rank to the same values but doesn’t stop there and keeps incrementing with the other values. For instance, if you have values 10, 20, 20, 30, then ranks will be 1, 2, 2, 3.
• Rank_modified: The rank_modified assigns the same rank to similar values.
• Rank_unique: The rank_unique assigns a unique rank to each and every value. For example, If the values are 10, 20, 20, 30 then the assigned ranks will be 1,2,3,4 respectively.

37. What is the difference between Tableau and other similar tools like QlikView or IBM Cognos?

Tableau is different than QlikView or IBM Cognos for various reasons:

• Tableau is an intuitive data visualization tool simplifying the story creation by simple drag and drop techniques. On the other hand, BI tools like QlikView or Cognos convert data into metadata to let the users explore data relations. If your presentation runs around presenting data in aesthetic visualizations then opt for Tableau. If not, and might need a full BI platform then go for Cognos/QlikView
• The ease of use or extracting data details is easier in Tableau than compared to extensive BI tools like Cognos. With Tableau, your team members, be it a guy from sales can easily read the data and give insights. But with Cognos, only members with extensive tool knowledge are appreciated and welcomed.

Part 3:

1. What is the difference between Traditional BI Tools and Tableau?

2. What is Tableau?

• Tableau is a business intelligence software.
• It allows anyone to connect to the respective data.
• Visualizes and creates interactive, shareable dashboards.

3. What are the different Tableau Products and what is the latest version of Tableau?

Here is the Tableau Product family.

(i)Tableau Desktop:

It is a self-service business analytics and data visualization that anyone can use. It translates pictures of data into optimized queries. With tableau desktop, you can directly connect to data from your data warehouse for live up to date data analysis. You can also perform queries without writing a single line of code. Import all your data into Tableau’s data engine from multiple sources & integrate altogether by combining multiple views in an interactive dashboard.

(ii)Tableau Server:

It is more of an enterprise level Tableau software. You can publish dashboards with Tableau Desktop and share them throughout the organization with web-based Tableau server. It leverages fast databases through live connections.

(iii)Tableau Online:

This is a hosted version of Tableau server which helps makes business intelligence faster and easier than before. You can publish Tableau dashboards with Tableau Desktop and share them with colleagues.

(iv)Tableau Reader:

It’s a free desktop application that enables you to open and view visualizations that are built in Tableau Desktop. You can filter, drill down data but you cannot edit or perform any kind of interactions.

 (v)Tableau Public:

This is a free Tableau software which you can use to make visualizations with but you need to save your workbook or worksheets in the Tableau Server which can be viewed by anyone.

4. What are the different datatypes in Tableau?

Tableau supports the following data-types:

5. What are Measures and Dimensions?

Measures are the numeric metrics or measurable quantities of the data, which can be analyzed by dimension table. Measures are stored in a table that contain foreign keys referring uniquely to the associated dimension tables. The table supports data storage at atomic level and thus, allows more number of records to be inserted at one time. For instance, a Sales table can have product key, customer key, promotion key, items sold, referring to a specific event.

Dimensions are the descriptive attribute values for multiple dimensions of each attribute, defining multiple characteristics. A dimension table ,having reference of a product key form the table, can consist of product name, product type, size, color, description, etc.

6. What is the difference between .twb and .twbx extension?

• A .twb is an xml document which contains all the selections and layout made you have made in your Tableau workbook. It does not contain any data.
• A .twbx is a ‘zipped’ archive containing a .twb and any external files such as extracts and background images.

7. What are the different types of joins in Tableau?

The joins in Tableau are same as SQL joins. Take a look at the diagram below to understand it.

8. How many maximum tables can you join in Tableau?

You can join a maximum of 32 tables in Tableau.

9. What are the different connections you can make with your dataset?

We can either connect live to our data set or extract data onto Tableau.

• Live: Connecting live to a data set leverages its computational processing and storage. New queries will go to the database and will be reflected as new or updated within the data.
• Extract: An extract will make a static snapshot of the data to be used by Tableau’s data engine. The snapshot of the data can be refreshed on a recurring schedule as a whole or incrementally append data. One way to set up these schedules is via the Tableau server.

The benefit of Tableau extract over live connection is that extract can be used anywhere without any connection and you can build your own visualization without connecting to database.

10. What are shelves?

They are Named areas to the left and top of the view. You build views by placing fields onto the shelves. Some shelves are available only when you select certain mark types.

11. What are sets?

Sets are custom fields that define a subset of data based on some conditions. A set can be based on a computed condition, for example, a set may contain customers with sales over a certain threshold. Computed sets update as your data changes. Alternatively, a set can be based on specific data point in your view.

12. What are groups?

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.

13. What is a hierarchical field?

A hierarchical field in tableau is used for drilling down data. It means viewing your data in a more granular level.

14. What is Tableau Data Server?

Tableau server acts a middle man between Tableau users and the data. Tableau Data Server allows you to upload and share data extracts, preserve database connections, as well as reuse calculations and field metadata. This means any changes you make to the data-set, calculated fields, parameters, aliases, or definitions, can be saved and shared with others, allowing for a secure, centrally managed and standardized dataset. Additionally, you can leverage your server’s resources to run queries on extracts without having to first transfer them to your local machine.

15. What is Tableau Data Engine?

Tableau Data Engine is a really cool feature in Tableau. It’s an analytical database designed to achieve instant query response, predictive performance, integrate seamlessly into existing data infrastructure and is not limited to load entire data sets into memory.

If you work with a large amount of data, it does takes some time to import, create indexes and sort data but after that everything speeds up. Tableau Data Engine is not really in-memory technology. The data is stored in disk after it is imported and the RAM is hardly utilized. 

16. What are the different filters in Tableau and how are they different from each other?

In Tableau, filters are used to restrict the data from database.

The different filters in Tableau are: Quick, Context and Normal/Traditional filter are:

• Normal Filter is used to restrict the data from database based on selected dimension or measure. A Traditional Filter can be created by simply dragging a field onto the ‘Filters’ shelf.
• Quick filter is used to view the filtering options and filter each worksheet on a dashboard while changing the values dynamically (within the range defined) during the run time.
• Context Filter is used to filter the data that is transferred to each individual worksheet. When a worksheet queries the data source, it creates a temporary, flat table that is uses to compute the chart. This temporary table includes all values that are not filtered out by either the Custom SQL or the Context Filter.

17. How to create a calculated field in Tableau?

• Click the drop down to the right of Dimensions on the Data pane and select “Create > Calculated Field” to open the calculation editor.
• Name the new field and create a formula.

18. What is a dual axis?

Dual Axis is an excellent phenomenon supported by Tableau that helps users view two scales of two measures in the same graph. Many websites like Indeed.com and other make use of dual axis to show the comparison between two measures and their growth rate in a septic set of years. Dual axes let you compare multiple measures at once, having two independent axes layered on top of one another.

19. What is the difference between a tree map and heat map?

A heat map can be used for comparing categories with color and size. With heat maps, you can compare two different measures together.

A tree map also does the same except it is considered a very powerful visualization as it can be used for illustrating hierarchical data and part-to-whole relationships.

20. What is disaggregation and aggregation of data?

The process of viewing numeric values or measures at higher and more summarized levels of the data is called aggregation. When you place a measure on a shelf, Tableau automatically aggregates the data, usually by summing it. You can easily determine the aggregation applied to a field because the function always appears in front of the field’s name when it is placed on a shelf. For example, Sales becomes SUM (Sales).  You can aggregate measures using Tableau only for relational data sources. Multidimensional data sources contain aggregated data only. In Tableau, multidimensional data sources are supported only in Windows.

According to Tableau, Disaggregating your data allows you to view every row of the data source which can be useful when you are analyzing measures that you may want to use both independently and dependently in the view. For example, you may be analyzing the results from a product satisfaction survey with the Age of participants along one axis. You can aggregate the Age field to determine the average age of participants or disaggregate the data to determine what age participants were most satisfied with the product.

21. What is the difference between joining and blending in Tableau?

• Joining term is used when you are combining data from the same source, for example, worksheet in an Excel file or tables in Oracle database
• While blending requires two completely defined data sources in your report.

22. What are Extracts and Schedules in Tableau server?

Data extracts are the first copies or subdivisions of the actual data from original data sources. The workbooks using data extracts instead of those using live DB connections are faster since the extracted data is imported in Tableau Engine. After this extraction of data, users can publish the workbook, which also publishes the extracts in Tableau Server. However, the workbook and extracts won’t refresh unless users apply a scheduled refresh on the extract. Scheduled Refreshes are the scheduling tasks set for data extract refresh so that they get refreshed automatically while publishing a workbook with data extract. This also removes the burden of republishing the workbook every time the concerned data gets updated.

23. How to view underlying SQL Queries in Tableau?

Viewing underlying SQL Queries in Tableau provides two options:

• Create a Performance Recording to record performance information about the main events you interact with workbook. Users can view the performance metrics in a workbook created by Tableau.
  Help -> Settings and Performance -> Start Performance Recording
  Help -> Setting and Performance -> Stop Performance Recording.
• Reviewing the Tableau Desktop Logs located at C: Users My Documents My Tableau Repository. For live connection to data source, you can check log.txt and tabprotosrv.txt files. For an extract, check tdeserver.txt file.

24. How to do Performance Testing in Tableau?

Performance testing is again an important part of implementing tableau. This can be done by loading Testing Tableau Server with Tab Jolt, which is a “Point and Run” load generator created to perform QA. While Tab Jolt is not supported by tableau directly, it has to be installed using other open source products.

25. Name the components of a Dashboard.

• Horizontal – Horizontal layout containers allow the designer to group worksheets and dashboard components left to right across your page and edit the height of all elements at once.
• Vertical – Vertical containers allow the user to group worksheets and dashboard components top to bottom down your page and edit the width of all elements at once.
• Text – All textual fields.
• Image Extract – A Tableau workbook is in XML format. In order to extracts images, Tableau applies some codes to extract an image which can be stored in XML.
• Web [URL ACTION] – A URL action is a hyperlink that points to a Web page, file, or other web-based resource outside of Tableau. You can use URL actions to link to more information about your data that may be hosted outside of your data source. To make the link relevant to your data, you can substitute field values of a selection into the URL as parameters.

26. How to remove ‘All’ options from a Tableau auto-filter?

The auto-filter provides a feature of removing ‘All’ options by simply clicking the down arrow in the auto-filter heading. You can scroll down to ‘Customize’ in the dropdown and then uncheck the ‘Show “All” Value’ attribute. It can be activated by checking the field again.

27. How to add Custom Color to Tableau?

Adding a Custom Color refers to a power tool in Tableau. Restart you Tableau desktop once you save .tps file. From the Measures pane, drag the one you want to add color to Color. From the color legend menu arrow, select Edit Colors. When a dialog box opens, select the palette drop-down list and customize as per requirement.

28. What is TDE file?

 TDE is a Tableau desktop file that contains a .tde extension. It refers to the file that contains data extracted from external sources like MS Excel, MS Access or CSV file.
There are two aspects of TDE design that make them ideal for supporting analytics and data discovery.

• Firstly, TDE is a columnar store.
• The second is how they are structured which impacts how they are loaded into memory and used by Tableau. This is an important aspect of how TDEs are “architecture aware”. Architecture-awareness means that TDEs use all parts of your computer memory, from RAM to hard disk, and put each part to work what best fits its characteristics.

29. Mention whether you can create relational joins in Tableau without creating a new table?

 Yes, one can create relational joins in tableau without creating a new table.

30. How to automate reports?

You need to publish report to tableau server, while publishing you will find one option to schedule reports. You just need to select the time when you want to refresh data.

31. What is Assume referential integrity?

In some cases, you can improve query performance by selecting the option to Assume Referential Integrity from the Data menu. When you use this option, Tableau will include the joined table in the query only if it is specifically referenced by fields in the view.

32. Explain when would you use Joins vs. Blending in Tableau?

If data resides in a single source, it is always desirable to use Joins.  When your data is not in one place blending is the most viable way to create a left join like the connection between your primary and secondary data sources.

33. What is default Data Blending Join?

Data blending is the ability to bring data from multiple data sources into one Tableau view, without the need for any special coding. A default blend is equivalent to a left outer join. However, by switching which data source is primary, or by filtering nulls, it is possible to emulate left, right and inner joins.

34. What do you understand by blended axis?

In Tableau, measures can share a single axis so that all the marks are shown in a single pane. Instead of adding rows and columns to the view, when you blend measures there is a single row or column and all of the values for each measure is shown along one continuous axis. We can blend multiple measures by simply dragging one measure or axis and dropping it onto an existing axis.

35. What is story in Tableau?

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.

36. What is the difference between discrete and continuous in Tableau?

There are two types of data roles in Tableau – discrete and continuous dimension.

• Discrete data roles are values that are counted as distinct and separate and can only take individual values within a range. Examples: number of threads in a sheet, customer name or row ID or State. Discrete values are shown as blue pills on the shelves and blue icons in the data window.
• Continuous data roles are used to measure continuous data and can take on any value within a finite or infinite interval. Examples: unit price, time and profit or order quantity. Continuous variables behave in a similar way in that they can take on any value. Continuous values are shown as green pills.

37. How to create stories in Tableau?

There are many ways to create story in Tableau. Each story point can be based on a different view or dashboard, or the entire story can be based on the same visualization, just seen at different stages, with different marks filtered and annotations added. You can use stories to make a business case or to simply narrate a sequence of events.

• Click the New Story tab.
• In the lower-left corner of the screen, choose a size for your story. Choose from one of the predefined sizes, or set a custom size, in pixels.
• By default, your story gets its title from its sheet name. To edit it, double-click the title. You can also change your title’s font, color, and alignment. Click Apply to view your changes.
• To start building your story, drag a sheet from the Story tab on the left and drop it into the center of the view
• Click Add a caption to summarize the story point.
• To highlight a key takeaway for your viewers, drag a text object over to the story worksheet and type your comment.
• To further highlight the main idea of this story point, you can change a filter or sort on a field in the view, then save your changes by clicking Update above the navigator box.

38. What is the DRIVE Program Methodology?

Tableau Drive is a methodology for scaling out self-service analytics. Drive is based on best practices from successful enterprise deployments. The methodology relies on iterative, agile methods that are faster and more effective than traditional long-cycle deployment.

A cornerstone of this approach is a new model of partnership between business and IT.

39. How to use group in calculated field?

By adding the same calculation to ‘Group By’ clause in SQL query or creating a Calculated Field in the Data Window and using that field whenever you want to group the fields.

• Using groups in a calculation. You cannot reference ad-hoc groups in a calculation.
• Blend data using groups created in the secondary data source: Only calculated groups can be used in data blending if the group was created in the secondary data source.
• Use a group in another workbook. You can easily replicate a group in another workbook by copy and pasting a calculation.

40. Mention what is the difference between published data sources and embedded data sources in Tableau?

The difference between published data source and embedded data source is that,

• Published data source: It contains connection information that is independent of any workbook and can be used by multiple workbooks.
• Embedded data source: It contains connection information and is associated with a workbook.

41. Mention what are different Tableau files?

Different Tableau files include:

• Workbooks: Workbooks hold one or more worksheets and dashboards
• Bookmarks: It contains a single worksheet and it’s an easy way to quickly share your work
• Packaged Workbooks: It contains a workbook along with any supporting local file data and background images
• Data Extraction Files: Extract files are a local copy of a subset or entire data source
• Data Connection Files: It’s a small XML file with various connection information

42. How to embed views onto Webpages?

You can embed interactive Tableau views and dashboards into web pages, blogs, wiki pages, web applications, and intranet portals. Embedded views update as the underlying data changes, or as their workbooks are updated on Tableau Server. Embedded views follow the same licensing and permission restrictions used on Tableau Server. That is, to see a Tableau view that’s embedded in a web page, the person accessing the view must also have an account on Tableau Server.

Alternatively, if your organization uses a core-based license on Tableau Server, a Guest account is available. This allows people in your organization to view and interact with Tableau views embedded in web pages without having to sign in to the server. Contact your server or site administrator to find out if the Guest user is enabled for the site you publish to.

You can do the following to embed views and adjust their default appearance:

• Get the embed code provided with a view: The Share button at the top of each view includes embed code that you can copy and paste into your webpage. (The Share button doesn’t appear in embedded views if you change the show Share Options parameter to false in the code.)
• Customize the embed code: You can customize the embed code using parameters that control the toolbar, tabs, and more. For more information, see Parameters for Embed Code.
• Use the Tableau JavaScript API: Web developers can use Tableau JavaScript objects in web applications. To get access to the API, documentation, code examples, and the Tableau developer community, see the Tableau Developer Portal.

43. Design a view in a map such that if user selects any state, the cities under that state has to show profit and sales.

According to your question you must have state, city, profit and sales fields in your dataset.

Step 1: Double click on the state field

Step 2: Drag the city and drop it into Marks card.

Step 3: Drag the sales and drop it into size.

Step 4: Drag profit and drop it into color.

Step 5: Click on size legend and increase the size.

Step 6: Right click on state field and select show quick filter.

Step 7:  Select any state now and check the view.

44. Think that I am using Tableau Desktop & have a live connection to Cloudera Hadoop data. I need to press F5 to refresh the visualization. Is there any way to automatically refresh visualization every ‘x’ seconds instead of pressing F5?

Here is an example of refreshing the dashboard for every 5 seconds.

All you need to do is replace the api src and server url with yours.

<!DOCTYPE html>

<html lang=”en”>

<head>

<title>Tableau JavaScript API </title>

<script type=”text/javascript” src=”http://servername/javascripts/api/tableau_v8.js”></script>

</head>

<div id=”tableau Viz”></div>

<script type=’text/javascript’>

var placeholderDiv = document.getElementById(“tableau Viz”);

var url = “http://servername/t/311/views/Mayorscreenv5/Mayorscreenv2”;

var options={

hideTabs:True,

width:”100%”,

height:”1000px”

};

var viz= new tableauSoftware.Viz(placeholderDiv,url,options);

setInterval (function() {viz.refreshDataAsync()},5000);

</script>

</body>

</html>

Some Additional Tricky Tableau Interview Questions

45. Suppose my license expires today, will users be able to view dashboards or workbooks which I published in the server earlier?

If your server license expires today, your username on the server will have the role ‘unlicensed’ which means you cannot access but others can. The site admin can change the ownership to another person so that the extracts do not fail.

46. Is Tableau software good for strategic acquisition?

Yes! For sure. It gives you data insight to the extent that other tools can’t. Moreover, it also helps you to plan and point the anomalies and improvise your process for betterment of your company.

47. Can we place an excel file in a shared location and use it to develop a report and refresh it in regular intervals?

Yes, we can do it. But for better performance we should use Extract.

48. Can Tableau be installed on MacOS?

Yes, Tableau Desktop can be installed on both on Mac and Windows Operating System.

49. What is the maximum no. of rows Tableau can utilize at one time?

Tableau is not restricted by the no. of rows in the table. Customers use Tableau to access petabytes of data because it only retrieves the rows and columns needed to answer your questions.

50. When publishing workbooks on Tableau online, sometimes a error about needing to extract appears. Why does it happen occasionally?

This happens when a user is trying to publish a workbook that is connected to an internal server or a file stored on a local drive, such as a SQL server that is within a company’s network.

Part 4:

1. Compare Qlik View with Tableau.

2. How is the Context Filter different from other Filters?

• Whenever we create a Context Filter, Tableau will create a temporary table for this particular Filter set and other Filters will be applied on the Context Filter data like cascade parameters.
• Suppose, we have created a Context Filter on countries, USA and India, Tableau will create a temporary table for these two countries’ data and if we have any other Filters other will be applied on these two countries’ data if we don’t have any Context Filter, each record will check for all Filters.

3. What is the disadvantage of Context Filters?

• The Context Filter is not frequently changed by the user—if the Filter is changed, the database must be recomputed and the temporary table has to be rewritten, slowing performance.
• When we set a dimension to context, Tableau creates a temporary table that will require a reload each time the view is initiated. For Excel, Access, and text data sources, the temporary table created is in an Access table format. For SQL Server, MySQL, and Oracle data sources, we must have permission to create a temporary table on our server. For a multidimensional data source, or cubes, temporary tables are not created, and Context Filters defined which Filters are independent and which are dependent.

4. What are the five main products offered by Tableau?

Tableau offers five main products:

• Tableau Desktop
• Tableau Server
• Tableau Online
• Tableau Reader
• Tableau Public

5. What is the latest version of Tableau Desktop?

Tableau Desktop 2021.2 (as of June 23, 2021)

6. What is data visualization?

Data visualization refers to the techniques used to communicate data or information by encoding it as visual objects (e.g., points, lines, or bars) contained in graphics.

7. Why Tableau?

Whether our data is in an on premise database, a database, a data warehouse, a cloud application, or in an Excel file, we can analyze it with Tableau. We can create views of our data and share it with colleagues, customers, and partners. We can use Tableau to blend it with other data, and we can keep our data up to date automatically.

8. What are Filters? How many types of Filters are there in Tableau?

This is one of the most frequently asked Tableau developer interview questions. Have a clear idea on this! A Filter restricts unnecessary data; it shows the exact data we want. Basically, Filters in Tableau are of three types:

• Quick Filter
• Context Filter
• Data source Filter

9. What is aggregation and disaggregation of data?

Suppose, we have data like below:

Eid Ename Salary Dept

1.abc 2000 java

2.bbc 3000 .net

3.Krishna 2500 java

Madhu 300

5.Vamshi 3000 mainframes

1.abc 1000 testing

2.bbc 3000 tableau

3.krishna 5000.net

4.Madhu 7000 testing

vanshi 9000 tableau

1 abc 11000 Mainframes

2 bbc 13000testing

3 krishna 15000 java

4 Madhu 17000 .nte

5 vamshi 19000.net

Aggregation: To display aggregate data
Sum/avg salary by each individual employee
Drag ename on column and salary on rows, and we will get the sum (salary) of each and individual employee
now, change the measure type as Avg

Choose salary option: choose measure types as ‘Avg’

Disaggregation: To display each and every transaction

When we look at the aggregated data in the views above, each bar represents all transactions for a specific employee summed up or averaged into a single value. Now, say, we want to see the individual salary transactions for each employee. We can create a view like that by selecting Analysis > Aggregate Measures.

10. How to remove the Show All option from a Tableau Auto Filter?

Right-click on Filter > Customize > uncheck the Show All option

11. Can we use non-used columns (columns that are not used in reports but used in data source) in Tableau Filters?

Yes! For example, in a data source, if we have columns like EmpID, EmpName, EmpDept, Emp Designation, EmpSalary, and in reports we are using EmpName on columns and EmpSalary on rows, we can use EmpDesignation on Filters.

12. What is the benefit of Tableau Extract file over the live connection?

Extract can be used anywhere without any connection, and we can build our own visualizations without connecting to a database.

13. What is the different between twb and twbx file extensions. Please explain.

The file extension .twb is a live connection; it points to the data source. The user receiving .twb needs permission to access the said data source and no data is included.

On the other hand, .twbx takes the data offline and stores it as a package or zip-like file, thereby eradicating the need for permissions.

14. How to combine two Excel files with the same fields but different data (different years)?

Suppose, we have five different Excel files (2007.xls, 2008.xls, … 2011.xls) with the same fields (film name, genre, budget, rating, profitability, etc.) but with data of different years (2007 to 2011). Can someone tell me how can I combine the film name, genre, and profitability so that I can see the visualization of 2007 to 2011 in a single chart?

15. What is the maximum number of tables we can join in Tableau?

We can join a maximum of 32 tables; it is not possible to combine more than 32 tables.

16. What is the difference between joining and blending in Tableau?

Joins in Tableau

Suppose, our client is in the healthcare domain and using SQL Server as their database. In SQL Server, there may be many Tableau-like Claims Tables, Rejected Claims Table, Customer Table, etc. Now, the client wants to know the customer-wise claims and the customer-wise rejected claims table using the Joins. Join is a query that combines the data from two or more tables by making use of the Join condition.

We can join a maximum of 32 tables; it is not possible to combine more than 32 tables.

In Tableau, Joins can be performed in two ways:

• By making use of common columns
• By making use of common data types

If we create Joins on the fields, in Tableau, all the table names are suffixed with $. While performing Joins on multiple tables, always go with the less amount of data tables, so that we can improve the performance.

In Tableau, Joins are divided into two types:

• Equi Join
• Non-equi Join

Equi Join

In the Join condition, if we are using equality (‘=’) operator, then such a kind of join is called Equi Join. Equi Join is further divided into three types:

• Inner Join: Inner Join will load the only matching records from both tables. Below is the Inner Join condition:

Tableaa.id = Tableb.id

Outer Join: Outer Join is further divided into three types:
Left Outer Join: Displays the complete data from the left table + matching records from the right

Condition:

tablea.id(+)

Right Outer Join: Displays the complete data from the right table + matching records from the left

Condition:

tablea.id(+)=tableb.id

Full Outer Join: Loads the complete data from the left table and the right table

Condition:

Table A full outer join Table B ON tablea.id= tableb.id

Self-join: If we are performing Join to a table with itself such a kind of Join is called a Self-join.

Non-equi Join

In the Join condition, if we are using operators apart from the equality (‘=’) operator (such as, <, >, <=, >=, and =!), then such a kind of Join is called Non-equi Join.

Data Blending in Tableau

Consider the same client. Suppose, they are operating their services in Asia, Europe, NA, and so on, and they are maintaining Asia data in SQL, Europe data in SQL Server, and NA data in MySQL.

Now, our client wants to analyze their business across the world in a single worksheet. In this case, we can’t perform a Join. Here, we have to make use of the data blending concept.

Normally, in Tableau, we can perform the analysis on a single data server. If we want to perform the analysis of data from multiple data sources in a single sheet, then we have to make use of this new concept called data blending.

Data blending mixes the data from different data sources and allows users to perform the analysis in a single sheet. ‘Blending’ means ‘mixing’ and when we are mixing the data sources, then it is called data blending.

Rules to Perform Data Blending

In order to perform data blending, there are a few rules:

• If we are performing data blending on two data sources, these two data sources should have at least one common dimension.
• In that common dimension, at least one value should be matching.

In Tableau, we can perform data blending in two ways.

• Automatic way: Here, Tableau automatically defines the relationship between the two data sources based on the common dimensions and based on the matching values, and the relationship is indicated in orange.
• Custom or Manual way: In the manual or custom way, the user needs to define the relationship manually.

Data Blending Functionality

• All the primary and secondary data sources are linked by a specific relationship.
• While performing data blending, each worksheet has a primary connection, and optionally it might contain several secondary connections.
• All the primary connections are indicated in blue in the worksheet and all the secondary connections with an orange-colored tick mark.
• In data blending, one sheet contains one primary data source and it can contain n number of secondary data sources.

17. What are Dimensions and Facts?

• Dimensions are nothing but the descriptive text columns. Example: product name, city, etc.
• Facts are the measures (numerical values). Example: sales, profit, etc.

18. Can we place an Excel file in a shared location and use it to develop a report and refresh it in regular intervals?

Yes, we can do it, but for better performance we have to use Extract.

19. What is the difference between heat map and tree map?

• A heat map is a great way to compare categories using color and size. In this, we can compare two different measures.
• A tree map is a very powerful visualization, particularly used for illustrating hierarchical (tree-structured) data and for visualizing a part of or a whole relationship.

20. What is dual axes?

To display two measures in one graph, Tableau uses dual axes.

21. What is blended axis?

Here, multiple measures are shown in a single axis and all the marks are shown in a single pane.

• Drag a dimension in a column
• Drag the first measure in the column
• Drag the second measure in the existing axis
• Us/multiplemeasures_blendedaxes.html

22. What makes Tableau stand out?

This is another question which is you see in every Tableau interview questions and answers blogs. Get a clear idea through this answer. Tableau stands out for several reasons:

• First, most of the BI tools are pricey, but Tableau has a free offering (Tableau Public) and a very popular (also free) academic distribution.
• Tableau is well recognized by firms like Forrester Research to be one of the most easy-to-use and agile products currently available.
• On the other hand, unlike some of the other BI tools, Tableau is not a complete technology stack; It is mostly useful for visualization and analytics. We will need other products in addition to Tableau for heavier enterprise data ETL, maintenance, storage, etc.

23. How do we do testing in Tableau?

We can’t perform testing in Tableau. It is a data visualization software.

24. Can you get values from two different sources as a single input into parameter?

Tableau currently does not support the multi-valued parameters. Case Study: The “dynamic parameter with a blend” technique can be used to highlight a single value, but not multiple values because of the way it works. As Tableau parameters are not dynamic, we cannot “filter” the list of values at runtime.

25. How do we use parameters in Tableau?

We can use parameters with filters, calculated fields, actions, measure-swaps, changing views, and auto-updates.

26. What is the use of the new custom SQL query in Tableau?

Custom SQL query is written after connecting to data for pulling the data in a structured view. For example, suppose, we have 50 columns in a table, but we need just 10 columns only. So instead of taking 50 columns, we can write a SQL query. The performance will increase.

27. What are the differences between Tableau and other traditional BI tools?

This is another frequently asked Tableau interview questions. Tableau provides easy to use, best in class, visual analytic capabilities, but it does not help with plumbing (data foundation). We could, for example, marry SQL Server with Tableau to get the complete package. Tableau licenses are relatively expensive if we are looking to scale.

Traditional BI can handle it all but with significant upfront costs, higher consulting, hardware, and software costs. Among the mega-vendors, only Microsoft can provide a reasonable value proposition. Open-source vendors like Pentaho and Jaspersoft do not have an abundant-enough talent pool, yet.

28. What are the similarities and differences between Tableau and Palantir?

Palantir and Tableau are very different. Palantir has its roots in large data computer science problems involving security, payments, fraud detection, and the like. Its customers/investors include PayPal, CIA, and others.

Tableau is a visualization player, with roots in Stanford University Research. Its Visual Query Language (VizQL) allows users to build visualizations on top of the standard data warehouses or spreadsheets.

29. How to create cascading filters without using context filter?

Here, say, we have Filter1 and Filter2. Based on Filter1, we need to use Filter2 on the data. For example, consider Filter1 as ‘Country’ and Filter2 as ‘States.’

Let’s choose Country as ‘India’ and hence Filter2 should display only the states of India.

Choose options of Filter2 states:
select option of ‘Only relevant values’

30. Is Tableau good for a strategic acquisition?

Yes, for sure! It gives us data insights much more than the others. It helps us plan and point the anomalies and improvise our process for betterment.

31. How to display the top five and the last five sales in the same view?

Using filters or calculated fields, we can display the top five and the last 5 sales in the same view.

32. Suppose, without using a line/bar chart, I want to design a view to show the region-wise profit and sales. How should I go about doing it? Explain.

• Generate a map using cities
• Then, drag the profit and sales to Details
• Add the state as Quick filter

33. Design a view in a map such that if a user selects any state, the profit and sales in the cities under that state would show up.

If we want to show the sales and profit of each and every city under the states in the same worksheet, first, we should have State, City, Sales, and Profit fields in our dataset.

1. Double-click on the State field
2. Drag City and drop into Marks card (under the State field)
3. Drag Sales and drop into Size
4. Drag Profit and drop into Color
5. Click on Size legend and increase the size (75%)
6. Right-click on the State field and select Show Quick filter
7. Select any state and check whether we got the required view or not.
8. In this, the view size indicates the number of sales and the color indicates the profit values.
9. How to add custom color in Tableau?

Create Custom Color code in ‘Preferences.tps’

Documents » My Table Repository » Preferences.tps

Then, add custom color code
Note: In Tableau 9.0, we have a color picker option.

35. How can we combine a database and the flat file data in Tableau Desktop?

• Connect data twice, once for database tables and then for the flat file. The Data->Edit Relationships
• Give a Join condition on the common column from DB tables to the flat file

36. What does Tableau do?

This is another most asked question which will help you in Tableau interview preparation. Tableau’s major goal is to help people see and understand data. Its software products put the power of data into the hands of everyday people, allowing a broad population of business users to engage with their data, ask questions, solve problems, and create values.

37. What is Tableau Public?

Tableau Public is a free service that lets anyone publish interactive data to the web. Once on the web, anyone can interact with the data, download it, or create their own visualizations for it. No programming skills are required here. We can also check out the gallery to see some of the things people have been doing with it.

38. What is data modeling?

This question is present in any of the Tableau interview questions blogs. Get an idea on this. Data modeling is the analysis of data objects that are used in a business or other context and the identification of the relationships among these data objects. Data modeling is the first step in performing object-oriented programming.

39. What is your daily work process in Tableau?

I think we all work on different projects using Tableau, so the work begins from understanding the requirement, and then we have to get the required data, create a storyboard, create visualizations in Tableau, and then present it to the client for review.

40. What is parameters in Tableau? How do they work?

Parameters are dynamic values that can replace constant values in calculations, and they can serve as filters.

41. How does Tableau work with huge datasets?

Tableau’s performance is based on the performance of the data source. If the data source takes more time to execute a query, then Tableau must wait up to that time.

42. How will you publish and schedule a workbook in Tableau Server?

• First, create a schedule for a particular time and then create Extract for the data source and publish the workbook on the server.
• Before we publish it, there is an option called ‘Scheduling and Authentication’. Click on that and select the schedule from the drop-down and then publish. Also publish data source and assign the schedule. This schedule will automatically run for the assigned time and the workbook will get refreshed on a regular basis.

43. Distinguish between Parameters and Filters.

• Parameters are dynamic values that can replace constant values in calculations. Parameters can serve as Filters as well.
• Filters, on the other hand, are used to restrict the data based on a condition that we have mentioned in the Filters shelf.

44. How to view a SQL generated by Tableau Desktop?

Tableau Desktop Log files are located in C: Users My Documents My Tableau Repository. If we have a live connection to the data source, we need to check the log.txt and tabprotosrv.txt files. If we are using Extract, have to check the tdeserver.txt file. The tabprotosrv.txt file often shows detailed information about queries.

45. What is Page shelf?

Page shelf is a powerful part of Tableau that we can use to control the display of the output and the printed results of the output.

46. What are the major differences between Tableau 7.0 and Tableau 8.0?
47. New visualizations are introduced like tree map, bubble chart, and box and whisker plot.
48. We can copy worksheet directly from one workbook to another workbook
49. Introduced R script
50. How to create filled maps?

• Step 1: Build a Map View, double-click on a geographic field such as State, Area Code, Zip Code, etc.
• Step 2: Select the Filled Map Mark Type the Automatic mark type will show this type of view as circles over a map. On the Marks card, select Filled Map to color the geographic areas.
• Step 3: Drag a Field to the Color shelf, define how the locations are colored by dragging another field to the Color shelf.

48. Does a parameter have its own drop-down list?

Yes, it may have its own drop-down list. The entries we make in the Parameter while creating it can be viewed as items in the drop-down list.

49. How to rectify SQL performance for developed dashboards?

After the creation of dashboards, if we get a problem from the SQL side it means Custom SQ.

50. How is data blending different from data joining?

Data blending is the combining of data from two or more different sources. We can combine the data between two sources, such as Oracle, SQL Server, Excel, and others.

Example:

Consider the admission data given in a relational database and the admission target data given in an Excel spreadsheet. Now, to compare the actual admissions with the target admissions, we can perform data blending. Here, we will blend the data based on some common dimensions of both sources to access the measure of the Admissions target. We list the two sources involved in data blending as the primary and secondary sources of the data. A left join is performed between the primary data source and the secondary data source, wherein all the data rows from the primary data source and only the matching data rows from the secondary data source are fetched.

Each data source in data blending includes its own collection of dimensions and measures. Data blending is useful when combining data from a variety of sources.

Data joining, on the other hand, is also combining data but from two or more tables or sheets within the same data source.

Example:

Combining two tables from the same SQL Server or Oracle Database or DB2 or any other data source. Combining two worksheets or more in the same Excel package will also fall under data joining.

Data joining is useful when combining data from a single source with several tables, sheets, or others.

51. Is it possible to store a huge amount of data in a memory engine using Tableau? If yes, how can we achieve that?

Yes, it is possible.

Yet, this question doesn’t have a straight answer since we can store massive amounts of data differently on the basis of the different configurations of Tableau Server implementation (such as 8 cores, 16 cores, etc.). Not just if Hyper is used or not, but other factors like server memory may also affect the amount of the data we can store.

Note: When dumping large amounts of data on Tableau Server, we have to make sure that this data volume should not affect the dashboard’s performance and the response time, and also, the processing time for extracts. This is where Tableau’s efficiency is enhanced by Hyper.

52. How is Tableau different from traditional reporting/BI tools?

Traditional BI solutions are powerful and can provide scaling and reliability. Various well-established software firms have endorsed them. These solutions provide ample security for data. Although, they need good BI technical knowledge and skills to work with them. Oracle BI and Qlikview are just two simple tools used among them.

Tableau is one of the top BI tools used in the industry today, providing easy operation and understanding without much knowledge of BI competencies. It has simple drag-and-drop functionality and a smart way to categorize the fields of data. However, in Tableau Public, data security is not provided, while in the Professional version, security is enabled.

53. What is the difference between INDEX and RANK in Tableau?

RANK and INDEX come under table calculations in Tableau. INDEX mainly deals with a record’s physical position. Incremental numbers are assigned according to the record’s physical order.

Whereas, RANK deals with a record’s value. The highest value gets the highest rank and the lowest value gets the lowest rank.

54. How to automate reports in Tableau?

We will see the option to schedule reports when uploading a report on Tableau Server. We can click on this button to set the time to refresh the data.

55. Suppose, my license expires today. Can my users be able to view the dashboards or workbooks that I published in the server earlier?

If our server license expires today, our user name on the server will have the role ‘unlicensed’ which means that we cannot access but others can. The Site Admin can ‘Change Ownership’ to another person, so Extracts if enabled do not fail.

56. Assume that I am using Tableau Desktop and have a live connection to Cloudera Hadoop data. I need to press F5 to refresh the visualization. Is there any way to automatically refresh the visualization every x minutes instead of pressing F5 everytime?

Here is how we can refresh the dashboard in every 3 seconds:

• Replace api src and the server URL with ours. The interval below is for 3 seconds.
  Tableau JavaScript API

57. What is Tableau Desktop?

Tableau Desktop is based on breakthrough technology from Stanford University that lets us drag and drop to analyze data. It is a great data visualization tool, with which we can connect to data in a few clicks, then visualize and create interactive dashboards with a few more clicks.

58. What are the differences between Tableau, Good Data, and the other traditional BI tools (Business Objects, etc.)?

We can talk about the features and functionalities of them for days, but at a high level, there are four major differences:

• Speed: How fast can we get up and running with the system, answer questions, design and share dashboards, and then change them? This is where systems like Tableau and Good Data are far better than the old-school Business Intelligence tools like Business Objects or Congo’s. Traditional systems took months or years to implement, with costs running to millions. Tableau has a free trial version that gets installed in minutes, and Good Data is cloud-based, so they are faster to implement by orders of magnitude. They are also faster in giving results: traditional BI requires IT and developers to make any changes to reports, so business users are mostly stuck in a queue waiting to get anything done. Tableau and Good Data provide more of a self-service experience.
• Analysis: This is where Tableau excels. It has a powerful and flexible drag-and-drop visualization engine based on some technology from Stanford. Good Data and traditional BI tools typically provide some canned reports but changing them requires significant time and money.
• Data layer: This is where the three options are the most different:
  • Good Data requires us to move our data to its cloud. Traditional BI typically requires us to move our data to its data warehouse. On the other hand, Tableau connects to a variety of existing data sources and also provides a fast in-memory data engine, essentially a local database. Since most enterprises have their data stored all over the place, this provides the most convenient choice and let’s companies use the investment they’ve already made.
• Enterprise readiness: Traditional BI and Tableau do well here, with enterprise-level security and high scalability.

59. What is Tableau?

Tableau is the Business Intelligence software that allows anyone to easily connect to data and then visualize and create interactive and sharable dashboards. It’s easy enough that any Excel user can learn it, but powerful enough to satisfy even the most complex analytical problems. With tableau, securely sharing the findings with others only takes seconds.

60 What is Tableau Server?

This is frequently asked basic Tableau questions for fresher’s. Go through this Tableau Server is a browser- and mobile-based insight anyone can use. We can easily publish dashboards with Tableau Desktop and share them throughout our organization. It’s easy to set up and even easier to run.

61. Explain the integration of Tableau with R.

R is a popular open-source environment for statistical analysis. Tableau Desktop can now connect to R through calculated fields and take advantage of R functions, libraries, and packages, and even the saved models. These calculations dynamically invoke the R engine and pass values to R via the Reserve package and they are returned to Tableau.

• Tableau Server can be configured to connect to an instance of Reserve through the tabadmin utility, allowing anyone to view a dashboard containing the R functionality.
• Combining R with Tableau gives us the ability to bring deep statistical analysis into drag-and-drop visual analytics.

62. What is the difference between the quick filter and the normal filter in Tableau?

Quick filter is used to view the filtering options and can be used to select options. Whereas, the Normal filer is something with which we can limit the options from the list or use some conditions to limit the data by field or value.

Part 5:

1. What is TABLEAU?

Tableau is the powerful and fastest visualizing tool that is used in the Business Intelligence (BI) Industry. It simplifies the raw data into an understandable format. Analysis of the data becomes faster with Tableau. The visualizations can be created in the form of dashboards. The visualizations or diagrammatic representation of data can easily be understood by the employees of the organizations who are at different levels.

2. What are the file size limitations with Tableau?

In Tableau, there are no limitations with the file sizes. And moreover, there is no row or column limit to import the data.

3. List out Tableau File Extensions.

The below ones are few extensions in Tableau:

1. Tableau Workbook (.twb)
2. Tableau Data extract (.tde)
3. Tableau Datasource (.tds)
4. Tableau Packaged Datasource (.tdsx)
5. Tableau Bookmark (.tbm)
6. Tableau Map Source (.tms)
7. Tableau Packaged Workbook (.twbx) – zip file containing .twb and external files.
8. Tableau Preferences (.tps)

4. What is the latest version of Tableau Desktop?

Tableau Desktop’s latest version is 2021.1(as of March, 25th 2021).

5. Define LOD Expression?

LOD Expression stands for Level of Detail Expression, and it is used to run complex queries involving many dimensions at the data sourcing level.

6. Define Heat Map?

A heat map is a graphical representation of data that uses the color-coding technique to represent different values of data. As the marks heat up due to their higher value, dark colors will be shown on the map.

7. Define Tree Map?

Tree Map is a visualization that organizes data hierarchically and shows them as a set of nested rectangles. The size and colors of rectangles are respective to their values of the data points they project. Parent rectangles will be tiled with their child elements.

8. What is the difference between a Heat map and Tree map?

Tree Map Heat MapIt represents the data hierarchically and shows them as a set of nested rectangles. It represents the data graphically which uses multiple colors to represent different values. It is used for comparing the categories with colors, size, and it can also be used for illustrating the hierarchical data and part to whole relationships. It is used for comparing the categories based on color and size. And also it is great in spotting the patterns based on the density of the information. The colors and size of rectangles are respective to the values of the data points when their values are higher or density of records, the data will represent in dark color.

9. What is a parameter Tableau? And how it works?

Parameters are dynamic values, we can replace the constant values in calculations.

10. What are the different data types in Tableau?

Tableau supports below data types. Data TypeMeaningExamplesStringCharacter Sequence. Enclosed in ”.Tableau’, ‘World ‘Number (Whole) Integers 9 Number (decimal) Floating values.123.45BooleanThey are logical values. TRUE, FALSEDateDate”02/01/2015″Date & Time Date and Time01 January 2019 05:55:00 PM Geographic Values Geographical Values India, Italy, Canada

11. Give a brief about the tableau dashboard?

Tableau dashboard is a group of various views which allows you to compare different types of data simultaneously. Datasheets and dashboards are connected if any modification happens to the data that directly reflects in dashboards. It is the most efficient approach to visualize the data and analyze it.

12. Define Page Shelf in Tableau?

Page shelf breaks the views into a series of pages. It displays an alternate view on each page. Due to this feature, you can analyze the effect of each field into the rest of the data in the view.

13. Define the story in Tableau?

The story can be defined as a sheet which is a collection of series of worksheets and dashboards used to convey the insights of data. A story can be used to show the connection between facts and outcomes that impacts the decision-making process. A story can be published on the web or can be presented to the audience.

14. Give an overview of the fact and dimensions of the table?

Facts are numeric measures of data. They are stored in fact tables. Fact tables store that type of data that will be analyzed by dimension tables. Fact tables have foreign keys associating with dimension tables.

Dimensions are descriptive attributes of data. Those will be stored in the dimensions table. For example, customer’s information like name, number, and email will be stored in the dimension table.

15. State some ways to improve the performance of Tableau

• Use an Extract to make workbooks run faster
• Reduce the scope of data to decrease the volume of data
• Reduce the number of marks on the view to avoid information overload
• Try to use integers or Booleans in calculations as they are much faster than strings
• Hide unused fields
• Use Context filters
• Reduce filter usage and use some alternative way to achieve the same result
• Use indexing in tables and use the same fields for filtering
• Remove unnecessary calculations and sheets

16. Explain different connection types in Tableau?

There are 2 connection types available in Tableau.

Extract: Extract is a snapshot of data that will be extracted from the data source and put into the Tableau repository. This snapshot can be refreshed periodically fully or incrementally. This can be scheduled in Tableau Server.

Live: It creates a direct connection to the data source and data will be fetched directly from tables. So, data will be up to date and consistent. But, this also affects access speed.

17. What are the different Joins in Tableau?

Tableau works the same as SQL. So, it supports all Joins possible in SQL

• Left Outer Join
• Right Outer Join
• Full Outer Join
• Inner Join
  
  

18. What is Data Modelling?

Data modeling is the analysis of data objects that are used in a business or other context and also used as identification of the relationships among these data objects. It is the first step of doing object-oriented programming.

19. Define Dual-axis?

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.

20. Define 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 the 2nd on the existing axis.

21. Define shelves and sets?

Shelves: Every worksheet in Tableau will have shelves such as columns, rows, marks, filters, pages, and more. By placing filters on shelves we can build our own visualization structure. We can control the marks by including or excluding data.

Sets: The sets are used to compute a condition on which the dataset will be prepared. Data will be grouped together based on a condition. Fields which is responsible for grouping are known assets. For example – students having grades of more than 70%.

22. Explain the limitation of context filters in Tableau?

Whenever we set a context filter, Tableau generates a temp table that needs to refresh each and every time, whenever the view is triggered. So, if the context filter is changed in the database, it needs to recompute the temp table, so the performance will be decreased.

23. What is Mark Card in Tableau?

There is a card to the left of the view where we can drag fields and control mark properties like color, size, type, shape, detail, label, and tooltip.

24. Define published data source?

When you are ready to make a data source available to other tableau desktop users. You can publish it to the tableau server or online. Or else you can make it available by saving the same like embedded excel or text file.

25. Define dual axis?

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.

26. Define Bullet graph?

A bullet graph is a variant of Bar graph. It is responsible for comparing the performance of one measure with other measures.

27. Define Gantt chart?

Gantt chart displays the progress of value over the period. It consists of bars along with the time axis. It is a project management tool. Here, each bar is a measure of a task in the project framework.

28. Define a Histogram chart?

A histogram chart shows the distribution of continuous information over a certain period of time. This chart helps us to find extreme points, gaps, unusual values, and more concentrated values.

29. What is data visualization?

Data visualization means the graphical representation of data or information. We can use visual objects like graphs, charts, bars, and a lot more. Data visualization tools provide an accessible way to see and understand the data easily.

30. What is Tableau Reader?

Tableau Reader is a free desktop application, where you can read and interact with the Tableau packaged workbooks. It can only open the files but cannot create new connections to the workbook.

31. What is the difference between published data and embedded data sources?

The published data source contains connection information that is independent of workbooks and can be used by multiple workbooks.

The embedded data source contains connection information but it is associated with the workbooks.

32. What is the Hierarchy in Tableau?

When we are working with large volumes of data, incredibly data may be messed. With Tableau, you can easily create hierarchies to keep your data neat. Even if you don’t need it, it is built into your data, which you can easily manage or organize the data and you can track the data easily.

33. What is a Column chart?

A column chat visualizes the data as a set of rectangle columns, as their lengths are proportional to values when they represent the data. The horizontal axis shows the category to which they belong, and the vertical axis shows the values.

34. What is the Bar Chart in Tableau?

The bar chart visualizes the data as a set of rectangle bars, as their values are proportional to lengths when they represent the data. The vertical axis shows the category to which they belong to and the horizontal axis shows the values. So, the bar chart is a vertical version of the Column chart.

35. What is the Line Chart?

The line chart is a popular type of diagrammatic way for visualizing the data, it connects the individual data points to view the data. We can easily visualize the series of values, we can see trends over time or predict future values. The horizontal axis holds the category to which it belongs and the vertical axis holds the values.

36. What is a Stacked Bar chart?

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. A stacked bar chart makes 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.

37. What is a Stacked Column Chart?

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 chart should be checked when the number of series is higher than two.

38. What is an Area Chart?

An area chart is nothing but line chat, the area between the x-axis and lines will be color or patterns. These charts are typically used to represent accumulated totals over time and are the conventional way to display stacked lines.

39. How to download Tableau Public?

 Step 1: Go to public.tableau.com and enter your e-mail address and click “Download the App “.

Step 2: After downloading the file, run the file and follow the prompts to install the Tableau.

Step 3: Now, you can see the Tableau shortcut on your desktop.

Step 4: Double click on the icon, to load tableau public. Now you see the screen as below.

40. What is Context Filter and show the steps on how to create the Context Filter Tableau?

Context Filters are applied to the data rows before any other filters. They are limited to views, but they can be applied on selected sheets. They define Aggregation and Disaggregation of data in Tableau

Step 1: Drag the subcategory dimensions to the row shelf and measure sales to the column shelf. Now choose the horizontal bar chart as chart type and again drag the sub-category dimensions to the filter shelf. Then we will get the following chart.

Step 2: Right-click on the Sub-Category field in the filter shelf and go to the Top fourth tab. Choose the option field, from the next drop-down and choose the option Top 10 by Sales Sum as shown in the following screenshot.

Step 3: Drag the dimension Category to the filter shelf. Give right-click on the general tab to edit and under that choose Furniture from the list. As you can see the result shows three subcategories of products.

Step 4: Right-click the Category: Furniture filter and select the option Add to Context. This produces the final result, which shows the subcategory of products from the category Furniture which are among the top 10 subcategories across all the products.

41. What are the products offered by Tableau? Explain a few things about them.

Tableau has 4 main products.

Tableau Prep: Tableau Prep is responsible for preparing data for analysis. This tool provides 3 coordinated views which provide us with a complete picture of data.

Tableau Desktop: Tableau Desktop is the place where the analysis happens. It has a powerful drag and drops analytics which is very easy to use. Through the desktop, you get your data insights quickly.

Tableau Online: Tableau Online is a secure and scalable self-service analytics cloud tool. You can use it anywhere, anytime and it has eliminated the complexities of IT.

Tableau Server: From small to large enterprises, Tableau server is used for fulfilling their BI requirements. This is an on premise solution. This tool can take data from anywhere and shared it across the organization through desktop or mobile browsers.

42. Differentiate parameters and filters in Tableau

Filters are the simpler and straightforward feature in Tableau. It applies to dimensions or measures directly. For example, to only show Gujarat or Karnataka in a State dimension, we can apply the filter on that. In Tableau, there are multiple UI options available for filters like radio buttons, drop-down lists, checkboxes, sliders, and more. Filters on sheets are also available in Tableau.

Parameters are like variables. They are complex and more powerful. Like a variable, a parameter can be used in calculations. So, that means, it only allows a single value. Parameters have the same UI options except for checkboxes because checkboxes don’t have a single value. For example, we can create a parameter for interest rate and period, and then we can use these parameters to calculate interest and principal payments.

43. Explain how many types of filters are available in Tableau?

Filters are used to provide the correct information to viewers after removing unnecessary data. There are various types of filters available in Tableau.

Extract Filters – Extract filters are used to apply filters on extracted data from the data source. For this filter, data is extracted from the data source and placed into the Tableau data repository.

Data source Filters – Data source filters are the same as extract filters. They also work on the extracted dataset. But, the only difference is it works with both live and extract connections.

Context Filters – Context Filters are applied on the data rows before any other filters. They are limited to views, but they can be applied on selected sheets. They define Aggregation and Disaggregation of data in Tableau

Dimension Filters – Dimension filters are used to apply filters on dimensions in worksheets. Dimension filters are applied through the top or bottom conditions, formula, and wildcard match.

Measure Filters – Measure filters are applied to the values present in the measures.

44. Differentiate between Tiled and Floating in dashboards?

In a tiled layout, items don’t overlap. The layout will be adjusted according to dashboard size. In the floating layout, items can be placed on some other layers. Floating items can have fixed positions and sizes.

45. Categorize dimensions in Tableau?

Dimensions are divided into 9 various categories

Slowly ever-changing dimension: The value of the dimension changes over an amount of time for slowly ever-changing dimensions.

Example – student of worker

Chop-chop ever-changing Dimension: Value in the dimension is rapidly changing for chop-chop ever-changing dimensions.

Example – Age (It changes every second)

Unchanged Dimension: Values are constant for unchanged dimensions.

Example – Traffic Signals

Shrunken Dimension: A set of 1 dimension is termed as Shrunken Dimension.

Example – A week is shrunken dimension for the month

Junk Dimension: Junk values or unrelated dimensions are termed as Junk Dimension.

Conformed Dimension: If any dimension is provided by various business areas, then such a dimension is termed as Conformed Dimension.

Example – Time (9-5) for any company or hospital or college

Degenerated Dimension: Degenerated dimensions have primary keys only without any matter of info.

Role enjoying Dimension: If one dimension is employed in multiple roles, then they are termed as Role enjoying Dimensions.

Example – Date for e-commerce site order (Date of Order, Date of Shipment, Date of delivery)

Inferred Dimension: Empty dimensions are called inferred dimensions. They are usually used in ETL.

Example – Customer email which he may not enter while submitting any form will be filled as null.

46. What is VIZQL in Tableau?

VIZQL is Visual Inquiry Language. It is a combination of VIZ and SQL. It is similar to SQL language. But instead of SQL commands, the VIZQL language converts data queries into visual images.

47. Explain the disaggregation and aggregation of data in Tableau?

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.

48. State the components of the dashboard?

The dashboard consists of 5 components.

• Web: it consists of a web page embedded in the dashboard.
• Horizontal component: it is a horizontal layout container in which we can add objects.
• Vertical component: it is a vertical layout container in which we can add objects.
• Image Extract: it allows you to upload an image to the dashboard from a computer.
• Text: it is a small WordPad where we can format and edit the text.

49. Differentiate discrete and continuous data roles in Tableau

Discrete data roles consist of values that are separate and distinct. Discrete data roles can take individual values within a range. For Example – cancer patients in the hospital, no. of threads in a sheet, state. Discrete values are displayed as blue icons in the data window and blue pills on shelves. Discrete fields can be sorted.

Continuous data roles consist of any value within the finite or infinite intervals. For Example – age, unit price, order quantity. Continuous values displayed as green icons in the data window and green pills on shelves. Continuous fields cannot be sorted.

50. What is the difference between Traditional BI Tools and Tableau?

Traditional BI Tableau BI Architecture has hardware limitations. Tableau does not have dependencies. It does not support in-memory, multi-thread, and multi-core computing. It supports memory when used advanced technologies. It has a predefined view of data. It uses predictive analysis for various business operations. We should need a good knowledge of BI and skills. It is easy working and understanding without the knowledge of BI and the skills data security is provided data security is not provided for the public, whereas in the professional version.

51. Define performance testing in terms of Tableau

We can check the performance of Tableau in the following 2 ways.

• We can create performance recordings to keep track of performance details of main events while interacting with workbooks. Then, these performance metrics can be viewed by the user and analyzed. Navigation to start/stop performance recording is Help Settings and Performance>→ Start Performance Recording Help→ Setting and Performance → Stop Performance Recording
• Review the logs created by Tableau Desktop. The location for log files is C: Users My Documents My Tableau Repository.
• For live connection, check the log files log.txt and tabprotosrv.txt.
• For Extract connection, check the log file tdeserver.txt

52. What is the difference between .twb and .twbx extensions?

.twb: .twb means Tableau workbook. .twb is an XML sheet, it stores the data about your documents, stories, and dashboards. This file is the reference to the source file such as Excel or tde. This file will be linked to your source file when you save the TWB file. If you want to share your workbook you need to send both the workbook and data source file.

.twbx: It is a compressed file, where you have all files. It includes data source files, twb, and other files to produce the workbook. TWBX is obsolete for sharing because it will share the copy of the file instead of an original source file. .twbx is used for reports and we can view using the tableau viewer.

53. Why Tableau?

• Tableau is very simple and user-friendly.
• Tableau helps in analyzing the data and using this one can change the raw data into an understandable format.
• Users can blend the data with the other data to create their own views on the data and to share it with the customers, and colleagues.
• Users can manage a large amount of data.
• It can easily integrate with multiple data sources.
• Tableau can create complex graphs which simply look like pivot table graphs in Excel.
• It gives quick calculations on datasets.
• Users can create the visuals easily and switch between the types, to find the model to represent the user messages.

54. How to create a calculated field in Tableau?

Step 1: Select Analysis -> drop down will open -> Select create calculated field

Step 2: Calculation Editor Box will open, give the name to the calculated field.

Step 3: Enter a formula in the calculation editor.

Example: Sum (Profits)/Sum (Sales). (Calculation Editor validates the formula)

Step 4: Click, Ok.

Now, the new calculated field added to the data pane.

55. Are there any limitations of parameters in Tableau? If yes, give details.

Tableau dashboard allows the representation of parameters in four ways only. They don’t allow any multiple values like a filter can do. They only allow a single value.

56. State some reasons for the low performance of Tableau? Explain in detail.

Following are the reason for low performance

• Filters – filters need to create an extra query and if it used in large numbers and inefficiently then they can reduce the performance. So, it is advised to use filters whenever it is mandatory
• Live connection – Tableau extract works much better in comparison with a live connection.
• Data sources – a wrong query to a wrong data source can reduce performance. Also, the data source’s performance can also affect Tableau’s performance.

57. State some ways to improve the performance of Tableau.

Following are the few ways to improve the performance

• Use an Extract to make workbooks run faster
• Reduce the scope of data to decrease the volume of data
• Reduce the number of marks on the view to avoid information overload
• Try to use integers or Booleans in calculations as they are much faster than strings
• Hide unused fields
• Use Context filters
• Reduce filter usage and use some alternative way to achieve the same result
• Use indexing in tables and use the same fields for filtering
• Remove unnecessary calculations and sheets

58. Tell me different ways to use parameters in Tableau

• Filters
• Calculated fields
• Actions
• Measure-swaps
• Changing views
• Auto-updates

59. Can we see SQL generated by Tableau Desktop?

Tableau Desktop Log files are placed in C: Users My Documents My Tableau Repository. In case of live connection to any data source, check the log file “log.txt” and “tabprotosrv.txt” files. In case of extract connection to any data source, check the “tdeserver.txt” file which has detailed information about queries.

60. If the owner of the published workbook license expires, then can other users see those workbooks?

If the owner of a published workbooks license expires then his/her role will change to “Unlicensed”. He/She cannot access those workbooks, but others can. Only site admin can change the ownership of those workbooks.

61. Can we remove the all options from a Tableau auto-filter?

Follow few steps

1. Go to the Segment filter, Click on the small drop arrow which is on the right side.
2. Select Customize.
3. Then we can visible a small drop box under customize, uncheck the option for “All” Value.

62. Which one is better? Extract or Live connection?

Extract connection is better than live connection because extract connection can be used from anywhere, anytime without connecting to the database. We can construct our own visualizations on it irrespective of the database connection.

63. Tell me something about the workbook version controlled in Tableau.

Versioning of workbooks can be done in 2 ways in Tableau.

• At the desktop level, you keep copies of your changes and files or using 3rd party system like Microsoft TFS.
• At the server level, where you publish the data source and version will be saved in revision history on Tableau Server or Online. Reverting to a previous version is also possible here.

64. Where can we apply global filters?

Global filters can be applied to sheets, stories, and dashboards.

65. How to add custom color to Tableau?

To add custom color in Tableau, we need to follow 3 steps

• Generate custom color code and create it in “Preferences.tps”
• Navigate to Documents→ My Table Repository→ Preferences.tps
• Add a note for custom color code

66. Can we create cascading filters without using context filters?

Cascading filters means filter2 values are dependent on filter1 values. For Example, filter1 is country and if we select “India” for filter1, filter2 values should show all Indian states. This feature we can achieve by using the option “Only Relevant Values”.

67. How can we display the top and bottom 5 of records in a single Tableau view?

To achieve this, we need to create 2 views

• View1 which contains the top 5 records
• View2 which contains the bottom 5 records
• View3 which is a join of View1 and View2

68. State a few charts which we should not use with valid reasons

Below here are few charts which we should avoid.

• 3D Charts: Visual representation of numbers in 3D charts will be skewed and it makes it difficult to compare and analyze.
• Pie Charts: Pie charts are not that much accurate as bar charts. In Pie charts, we have areas and angles to compare instead of length in a bar chart. Areas and angles cannot be analyzed with ease.
• Donut Charts: This is the same as Pie chart, but here, we have a hole in the middle to make it look like a donut. Due to that hole, we need to compare arc length with other arcs to analyze the values. Comparing arcs lengths is also a difficult task for our eyes.

69. Do we have any way to handle null values in Tableau?

Tableau cannot plot null values on-axis. So, it will display an indicator at the lower right corner of the view. Once you click on that indicator, you have options to handle null values. Below are the options available to handle null values.

• Filter Data – If you choose this option, null values will be filtered out from the view.
• Show Data at Default Position – It replaces the null value with the default value and shows the data at the default position on-axis. These default values depend on the data type of field. Below here are the defaults of a specific data type.

• Numbers →0
• Dates → 12-31-1899
• Geographic Location → (0,0)
• Negative Values → 1

70. Do we have any data limitations in Tableau Public?

Yes, Tableau Public can only allow 10 million rows to users for data visualization.

71. Can we download views or workbooks from the server? If yes, in which data formats?

We can download views or workbooks from the server. But, data formats available to us depend on the permissions granted by site administrators or content owners.

• Image: .png format
• Data: .csv file.

We can also download selected sheets into PDF format, but while generating PDF, web page objects won’t be included.

72. Can we use unused columns (Columns that are not used in reports but data source has columns) in Tableau Filters?

Yes, we can use unused columns in tableau filters.

Let us consider one example.

In data source, I have column like emp_id, emp_name, emp_sal, emp_dep, emp_designation. But, in reports, I am using emp_name in columns and emp-sal in rows. I can use emp_designation on filters.

73. What is the benefit of the Tableau extract file over the live connection?

Extract files can be used without any connections and you can build your own visualization without connecting to the database.

74. How many tables join are possible in Tableau?

We can join 32 tables in Tableau.

75. Can we place an excel file in a shared location and use it to develop a report and refresh it in regular intervals?

Yes, we can place an excel file in a shared location and we can use it to develop a report, but for better performance, we need to extract the file.

76. How do we do testing in Tableau?

Yes, we can do testing in Tableau by using tools and the easiest way is using the desktop application. We need to check it before we publish it on the Tableau server.

77. Can you get values from two different sources as a single input into a parameter?

Tableau, currently not supporting the multi-valued parameters. As Tableau parameters are not dynamic, we cannot filter the list of values at runtime.

78. Design a view in a map such that if a user selects any state the cities under that state have to show profit and sales.

If you want to show the profit and sales of each and every city under the state in the same worksheet, then follow a few steps.

The data which you want to display under the state, it must be in the same worksheet.

• Double click on the state filed.
• Drag the city and drop it under the state (Mark Card).
• Drag the Sales and drop into the size.
• Drag the Profit and drop it into the color.
• Click on the size legend and increase the size (75%).
• Give a right-click on State filed and select show filter.
• Select the state and check whether you got the required view or not.

In the View, Size indicates the Sales, and Color indicates the profit of the respective state (which you have selected).

79. How can u set permissions or protect the data in tableau public?

Tableau does not have any security permissions or to protect the data in Tableau public. Whatever we shared in Tableau public those files, workbooks can be view by all users. There is no security option in Tableau public.

80. If I delete a workbook from tableau public and there are links to other blogs and other web locations. What happens to them?

Tableau public is like a repository, if you delete anything in the Tableau public the data will be lost, even if links are in other locations and blogs. We cannot access those links.

81. Mention whether you can create relational joins in Tableau without creating a new table?

Yes, we can create relational joins in Tableau without creating a new table

82. When publishing workbooks on Tableau online, sometimes an error about needing to extract appears. Why does it happen occasionally?

It happens when the user is trying to publish the workbook which is connected to the internal or local server that means the company’s network.

83. Can parameters have a drop-down list?

Yes, Parameters have their own drop-down list, which enables the users to view the data entries which are available in the parameter during the creation.

84. How do you optimize the performance of the dashboard?

1. Minimize the number of fields.
2. Minimize the number of records.
3. Reduce the marks (data points) in your view (remove unneeded dimensions).
4. Reduce the number of filters.
5. Use an include filter.
6. Use a continuous data filter.
7. Use action filters and parameters.
8. Reduce the number of nested calculations.
9. Remove custom SQL.
10. Clean up your workbooks.

85. How to use group in calculations field?

Option 1:

We can create the group by using the calculated field.

• Step 1: Select Analysis-> click the calculated field
• Step 2: Enter the field name (a dialogue box will appear)
• Step 3: Enter the calculation -> Click Ok.

Example:

IF [Container]=’Jumbo Box’ then ‘Big Containers’

ELSEIF [Container]=’Jumbo Drum’ then ‘Big Containers’

ELSEIF [Container]=’Large Box’ then ‘Big Containers’

ELSEIF [Container]=’Medium Box’ then ‘Midsize Containers’

ELSEIF [Container]=’Wrap Bag’ then ‘Midsize Containers’

ELSEIF [Container]=’Small Box’ then ‘Little Containers’

ELSEIF [Container]=’Small Pack’ then ‘Little Containers’

END

The above calculation creates the group with four values: Little Containers, Big Containers, Small Containers, and Midsize Containers.

Option 2:

Create a set from the group, and use the set in the calculated field.

Step 1: Right-click on the Data Pane and then select Create Set.

Step 2: Create a set dialogue box that will open, 

            Enter the field name.

            Select the group, on the general tab.

Step 3: Click Ok.

86. Can Tableau be installed on macOS?

Yes, Tableau can be installed on both the Windows Operating system and macOS.

87. How to automate reports in Tableau?

When we are publishing the reports to Tableau Server, there we will find an option to schedule the report, just select the time when you want to refresh the data.

88. Which databases give the best performance when connected live?

Native Database gives the best performance when connected live.

89. What are the challenges faced when working with huge volumes of data?

1. View running will be slow.
2. Data Extraction.
3. Alignment issues with data.
4. Testing Data.

90. State limitation of context filters in Tableau

Whenever we set a context filter, Tableau generates a temp table that needs to refresh each and every time the view is triggered. So, if the context filter will be changed, the database needs to recompute and rewrite the temp table, which in turn slows down the performance.

91. What is a marks card in Tableau?

There is a card to the left of the view where we can drag fields and control mark properties like color, size, type, shape, detail, label, and tooltip.

92. Define a published data source

The published data source has connection information in it. It is independent of any workbook and can be accessed by multiple workbooks.

93. Define blended axis

Multiple measures can share 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 the 2nd on the existing axis.

94. Can we remove the “All” option from the auto-filter in Tableau?

Yes, we can. Navigate to filter→ Right-click on it→ select customize→ uncheck the option “Show All”

95. Define Bullet graph

A bullet graph is a variant of Bar graph. It is responsible for comparing the performance of one measure with other measures.

96. Define Gantt chart

Gantt chart displays the progress of value over the period. It consists of bars along with the time axis. It is a project management tool. Here, each bar is a measure of a task in the project framework.

97. Define Histogram chart

A histogram chart shows the distribution of continuous information over a certain period of time. This chart helps us to find extreme points, gaps, unusual values, and more concentrated values.

98) What is Tableau Public?

Tableau Public is an open-source and free service that allows anyone to publish the data source and visualizations to the web. These visualizations can then be embedded into blogs or web pages. They can also be distributed through email or social media. Moreover, they can be made downloadable by other end users. For Tableau Public, no programming skills are needed. It can be accessed by anyone free of cost.

Part 6:

1. What are data types? What data types does Tableau support?

Data types refer to the kind of data that a user can enter into Tableau as an input. Each data type is treated differently by Tableau, and the data type of a field decides the operations that can be conducted on it. 

The data types supported by Tableau are:

• Text
• Date
• Date and Time
• Numerical
• Boolean
• Geographical

2. What are the dimensions and measures in Tableau?

Dimensions and measures can be understood on the basis of the type of data that they can hold. Dimensions are a container of qualitative values, which includes the string, date, and geographical data types. These are generally used for the filtering and classification of your data. Measures are numerical values. They can also be used for classification but additionally can be used for aggregation and mathematical formulations.

3. What is Discrete and Continuous in Tableau?

In Tableau, a Discrete dimension or measure is one in which each entry is treated as separate and different from the other entities. Product Names, Countries, etc., are examples of discrete dimensions. On the other hand, a Continuous dimension or measure is one that is treated as a part of a series. This includes dimensions such as Dates and Years.

4. What are Filters in Tableau?

In Tableau, filters can be used to restrict the amount of data that you can view at any point in time or the amount of data that you include in your analysis. For example, if you contain ten years’ worth of profit data for your company but want to show only the last three years, you can use a Filter to ensure the same.

5. What are the different filters that can be used in Tableau?

There are several different types of filters that Tableau supports, and each of these performs a different task. The types of filters in Tableau are as follows.

• Filters on Measures
• Filters on Dimensions
• Context Filters
• Extract Filters
• Data Source Filters
• Table Calculation Filters

6. What is joining in Tableau?

When working with data, it is very seldom that we have to deal with only one data set. Often, the same data can be distributed across two or more datasets, and you might need to merge or take an intersection of the datasets in order to facilitate their analysis. This activity is known as Joining.

7. What are the different types of Joins in Tableau?

The different types of Joins in Tableau as follows:

• Inner: An intersection of two tables is taken in which only the common values of both tables are included.
• Left: The final table includes the entire left table but only the matching values from the right table.
• Right: The final table includes the entire right table but only the matching values from the left table.
• Outer: In the final table, all values from both tables are included, and the matches are merged.
• Union: In this, a simple union is done, and the values of one table are appended to another.

8. Compare Blending and Joining in Tableau.

The primary difference between Blending and Joining in Tableau arises from the source of the data. In Joining, data will typically emanate from the same source, such as two Excel worksheets. The data will have the same dimensions and measures regardless of where it comes from. On the other hand, in Blending, the data will have different sources. When data from an SQL server is to be combined with data from an Excel sheet, it is termed as Blending. The dimensions and measures in both data sources may be different.

9. What is the difference between an Extract and a Live Connection?

An Extract reflects the part of the data source that was added to Tableau at the time that it was added. If a change has been made to the data source after its addition to Tableau, this change will not be reflected. A Live Connection represents the data source as it is at present, and all changes in the original data source will be reflected in Tableau as well.

10. What are Calculated Fields?

A Calculated Field is a user-created field that can include operations on other fields that are present in the data. A calculated field does not impact the original data but rather creates a new field that contains the results of the operations conducted on the data.

11. What are Groups in Tableau?

A Group in Tableau is a collection of categories that can be used to create a single overarching subcategory. An example can be considered from the Superstore data set, in which several different product subcategories are present. You can create a group of any number of these subcategories and create a single category for analysis.

12. What are Sets in Tableau?

A Set is similar to a group but deals with the output rather than the input. A Set is a collection of the output values associated with a particular category or group of categories. In the superstore dataset, if you are plotting the profit of all categories, you can create a Set of the profits of any number of categories.

13. What are Parameters?

A Parameter is a dynamic value that saves you the inconvenience of having to change your filter repeatedly. You can create a Parameter in place of constant values in your filters, reference lines, and calculations and make changes in these from the Dashboard itself.

14. What is a Heat Map?

A heat map is a qualitative method of the visualization and comparison of data. Using a heat map, you can compare the quantum method of measures across various categories within a table itself without needing to create a graph or chart. In general, higher values will be shown in darker shades of red, while lower values will tend toward the blue end of the spectrum. However, Tableau does allow you to change colors and shades.

15. What is a Treemap?

A treemap allows you to quantitatively analyze data based on the size of the pictorial representation. The basic unit of a treemap is a rectangle. A large rectangle represents the sum of all values of your chosen measures. This rectangle is then divided into further smaller rectangles based on the value of the measure in each of the categories of your chosen dimension.

16. What is the difference between a TWB and a TWBX file?

A TBW file is the basic Tableau file, which contains instructions regarding how Tableau interacts with a particular source of data. However, the data source needs to be attached separately and placed at an appropriate location for Tableau to interact with it. A TWBX file is a Tableau package, which contains the entirety of the data to be analyzed as well as the analysis.

17. What is the difference between a Tableau Worksheet and Workbook?

A Tableau Worksheet contains raw data, which can be an extract of the original source or a live connection to the data. It contains rows and columns which have values of measures and dimensions.

A Tableau Workbook is a collection of sheets in Tableau. These sheets may be workbooks, dashboards, or stories.

18. What is the difference between a Tableau Dashboard and Story?

A Tableau Dashboard may be considered to be a group of pictorial representations based on data derived from multiple worksheets. In a Dashboard, you can arrange multiple views to convey a central message.

A Tableau Story is a collection of Dashboards, which is typically used to present a collection of takeaways from the data.

19. What is a blended axis?

Very often, in Tableau, you may need to present multiple graphs in the same Cartesian plane. These graphs may have to be derived from different measures. You can do so with a blended y-axis. The caveat to incorporating a blended axis is that the unit and scale of the two measures must be the same.

20. What is a dual-axis?

A dual-axis is used to plot two measures with different units on the Cartesian plane. Typically, one y-axis will be located on the left and the other on the right. You will need to determine the scales for both axes independently.

21. What are the different user roles in Tableau?

There are several different user roles available in Tableau. The user roles are as follows.

• Server Administrator
• Site Administrator
• Publisher
• Interactor
• Viewer
• Unlicensed

22. What is the use of user roles in Tableau?

User roles determine how a particular user interacts with a Tableau Workbook. Especially at the enterprise level, user roles are essential since the number of people who actively work on a task is generally much fewer than the number of people who will be viewing the workbook. User roles restrict editing rights and allow the Workbook to be maintained in its original form. Changes can be carried out only by authorized persons.

23. What are the disadvantages of using a context filter in Tableau?

The primary disadvantage of using a context filter is the long time period involved in implementing the filter. Especially when dealing with large amounts of data, Tableau can take a lot of time in placing a filter in context and also lead to some load on your memory capacity.

24. What are the different file extensions associated with Tableau?

There are several different file extensions that Tableau has led to the creation of, and each of them serves a separate purpose. These file extensions are as follows.

TDE: Tableau Data Extract

TPS: Tableau Preferences

TWBX: Tableau Packaged Workbook

TDS: Tableau Data Source

TDM: Tableau Bookmark

TDSX: Tableau Packaged Data Source

TMS: Tableau Maps Source

TWB: Tableau Workbook

25. What is the Tableau data engine?

The Tableau data engine is the main driving force behind data analysis in Tableau. It is an analytical database, capable of instance query response reception and predictive performance. It does not utilize the memory of the system to a great extent.

26. What is the difference between embedded and published data sources?

An embedded data source is a source that I associated with a particular workbook. It cannot be used by other workbooks unless it is imported into them. In contrast, a published data source may be considered a global source that multiple workbooks can utilize.

27. What is serialization?

Serialization is the process of the conversion of an object or data structure into a bit sequence. This aids in the storage of files as well as their transfer across a network.

28. What are the different types of authentication in Tableau?

There are two ways that authentication may be carried out in Tableau. These are local authentication and active directory.

29. What is meant by a Page Shelf?

A Page Shelf is a capability offered by Tableau which allows a user to control the way the viewers can study the data. The views created by the user are divided among a number of pages, each of which may deal with a different theme. The pages are generally modular and can be flipped through.

30. What are the row and column limitations for the import of data in Tableau?

There are no row or column limitations for importing data into Tableau. Additionally, there are also no limitations to file size.

31. What is data modeling?

Data modeling is used to refer to the analysis and interpretation of data. It uses advanced data informatics tools in order to determine the relationship between several extracts of data and come up with a legible recommendation, especially in an enterprise setting.

32. What are shelves in Tableau?

Shelves are prominent regions in a Tableau dashboard that contain fields, columns, rows, filters, and marks. You can interact with shelves by dragging the fields to be analyzed into them as well as the fields that will act as the analysis filters.

33. What is a Tableau Reader?

A Tableau Reader is a standalone software that can allow users to read Tableau files. However, users cannot interact with the files in order to edit them or create connections to other Tableau files.

34. What is a Hierarchy?

In Tableau, a hierarchy can be used to manage data. Especially when your data set is considerably large, hierarchies – either pre-created or created by the user – can be useful in managing data and analyzing it more efficiently.

35. What is a Tableau Server?

A Tableau server is an offering meant especially for enterprises. When working with a group of people, it can often be useful to be able to share your Tableau workbook for collaboration or review. Using a Tableau server, you do not need to store local copies of your workbook and can seamlessly share them across the organization.

36. What are Tiled and Floating Dashboards?

A Tiled Dashboard contains only a single layer, on which views can be arranged with well-defined borders in rectangular form. In a Floating Dashboard, there is no restriction on where views can be placed. There are multiple layers, and views are allowed to overlap.

37. What do you mean by VIZQL?

VIZQL is used to refer to Visual Inquiry Language and is a blend of VIZ and SQL. It is identical in nature to SQL, but a major difference is that it does not convert queries into SQL commands but rather into images.

38. How is Tableau Different from traditional business intelligence tools?

The primary difference between Tableau and traditional BI is in the amount of knowledge required to use them. You do not need coding or BI knowledge in order to analyze your data using Tableau. Additionally, traditional BI tools do not have predictive powers like Tableau and also do not support in-memory computing. However, security considerations in traditional BI are more robust than in Tableau.

39. Which elements of Tableau can cause a lag in its performance?

There are several Tableau elements that, when not used prudently, can cause a performance reduction. The greatest among these elements is the Filters. Filters can take long minutes to yield results if your data is large and contains a significant number of queries. A live connection generally needs to refer to the original source of data for most commands and hence extracts work much better performance-wise. Similarly, a query to a wrong or unavailable data source can also cause a lag.

40. Is it possible to view the SQL commands generated by Tableau?

Yes, it is possible to view the SQL commands generated by Tableau. If your workbook has a live connection to a data source, you may go to the My Tableau Repository, generally located in My Documents, and check log.txt and tabprotosrv.txt. If you were working on a data extract, you might check tdeserver.txt.

41. What is a bookmark in Tableau?

A bookmark is a convenient method to share your work in a limited amount of time. It contains only a single spreadsheet that can be shared.

42. What are the distinguishing features of a data source?

The distinguishing features of a data source are its name, the type of connection it has, the worksheets that it connects to, and whether it is a live connection or an extract.

43. What are the limitations of Tableau?

A major limitation of Tableau is that the columns cannot be defined individually. Additionally, it is hard for users to control the selection and sorting of columns in a worksheet.

44. What are the advantages of using Tableau?

There are several advantages that come with using Tableau for data analysis. Tableau can be much faster than other BI software and is also much easier to use. It allows you to establish a direct connection with your data and makes publishing and sharing easy.

45. What are the components of a Tableau Server?

The components of a Tableau Server are as follows.

• Gateway
• Data server
• Data engine
• Backgrounder
• Repository
• Search and license
• Application server
• VIZQL server

46. What are data extract files?

Data extract files are Tableau files that contain either a whole dataset or a part of a dataset. They can be useful if you are looking to transfer a copy of your dataset across a network. They also improve the performance of Tableau. Tableau data extract files have the extension TDE.

47. What are user functions?

User functions can be used to determine the access of users in Tableau. They are especially useful in an enterprise setting and can be applied to users either on a Tableau Server or Tableau Online.

48. What are custom territories?

Tableau is among the first BI software to offer the capability to picturise data in the form of maps. In a map, you are not restricted to just individual countries or continents. Rather, you can create custom groupings of countries known as custom territories.

49. What is a mark card?

A mark card is a panel in Tableau that can be used to control the visual features of the view. You can change the color, labels, font size, type, and detail of the view using the mark card.

50. List the products that Tableau offers.

Tableau has four main offerings. These four offerings are as follows.

• Tableau Prep
• Tableau Desktop
• Tableau Server
• Tableau Online

51. What are the types of dimensions in Tableau?

Dimensions in Tableau can be divided into nine broad categories. These categories are as follows.

• Slowly ever-changing dimension
• Chop chop ever-changing dimension
• Shrunken dimension
• Junk dimension
• Unchanged dimension
• Degenerated dimension
• Inferred dimension
• Conformed dimension
• Role enjoying dimension

52. What do you mean by a role enjoying dimension?

A role enjoying dimension is a dimension that is used for multiple purposes in the same workbook. An example of such a dimension can be the date in an ecommerce dataset.

53. With which components of Tableau can parameters be used?

Parameters can be used with the following components of Tableau.

• Measure swaps
• Actions
• Filters
• Changing views
• Calculated fields
• Auto updates

54. How are Palantir and Tableau different?

Among the major differences between Tableau and Palantir lies in the applications for which they are used. Palantir is used for computer science problems involving large amounts of data in fields such as security and fraud detection. On the other hand, Tableau is a data visualization software that is used for business intelligence applications.

55. How do you add a custom color in Tableau?

To add a custom color in Tableau, you need to access the preferences.tps file and create a new color code. Starting with Tableau 9.0, a color picker option is also available.

56. What is the difference between RANK and INDEX?

RANK and INDEX are used for different purposes. RANK is utilized to assign an index or key to an entry on the basis of its value. INDEX assigns this number to an entry on the basis of its location in the table.

57. Is it possible to automate reports in Tableau?

Yes, Tableau has an effective mechanism to automate reports. When you are uploading a report to the Tableau Server, you will receive an option to schedule reports. Using this functionality, you can communicate how often or when you want data to be refreshed.

58. In case of the license expiry of a workbook owner, does access to the workbook cease for all users?

In case a workbook owner’s license expires, the user role of the owner will change to Unlicensed. The owner will then not be able to access the workbook, but all others who had access to it will be able to. The Site Admin can also transfer ownership so that there is no failure of extracts.

59. Can R and Tableau be used together?

Tableau users who are also proponents of the data analysis capabilities of R can now integrate both these programs through calculated fields. Calculated fields offer support for R commands, functions, and libraries. R is invoked by calculated fields, and the final value is returned to Tableau.

60. What is the greatest number of tables that you can join in Tableau?

You cannot join more than 32 tables in Tableau.

61. What are filter actions?

The relationship between source sheets and action sheets is described through filter actions. If a guided logical path is being built in a workbook or dashboard, filter actions can be of great use to a developer.

62. Where are global filters applicable?

Global filters can be used by developers in Dashboards and Stories, as well as in Sheets.

63. How does a developer get the current date and time in Tableau?

The current date and time are procured in Tableau using the NOW() function.

64. What are the methods of forecasting available in Tableau?

The only method of forecasting available in Tableau is exponential smoothing.

65. What is the application server in Tableau?

In Tableau, authentication and authorization are provided through the application server. The permissions for mobile as well as web versions of Tableau are handled through this server.

66. What is a measure filter?

A measure filter makes it possible to filter a field based on the values included in it. Data can be modified using aggregated values in a measure filter.

67. What is LOD?

LOD stands for Level of Detail. A LOD expression is used at the data source level for queries involving a large number of dimensions.

68. What is a bin?

Bins are equidistant collections of data defined by the user. The data that is eligible for a bin is assigned to it, and views are then created accordingly. Bins are most typically used in histograms.

69. What is a backgrounder?

A backgrounder is a specific application for handling background tasks associated with Tableau. It uses extra memory available in the processor in order to complete background activities such as refreshing extracts, communicating notifications, and handling background assignments.

70. What is disaggregation in Tableau?

Disaggregation is used to study every entry in the source of data. It is especially useful when conducting a study of outliers or when both dependent and independent data is involved.

71. What are the types of data sources that are compatible with Tableau?

There is a wide variety of data sources that are compatible with Tableau. Here are the main data sources that you can import your data to Tableau from.

• XLS and CSV files
• SQL Server, Oracle, and other relational systems
• Google BigQuery, Microsoft Azure, and other cloud systems
• Database connection sources

72. What are the types of LODs?

There are three primary types of LODs, which are as follows.

• Fixed LOD
• Include LOD
• Exclude LOD

73. What is a Fixed LOD?

A fixed LOD is an expression used for the computation of values without making an explicit reference to any dimensions.

74. Why are trend lines used?

Trends lines are used in forecasting to pictorially represent the direction in which data is headed. Trend lines allow you to forecast the future trend of an extract of data or just to prove a correlation between two quantities.

75. Can you define custom regions in Tableau that are not defined by country borders?

No, Tableau does not currently provide the capability to define borderless custom regions.