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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.

To clear interview for Tableau, follow these tips:

• Focus on the fundamentals: What is Tableau and its working. How calculations work or how a query is processed when visualization is created.
• Thoroughly know about Dimensions and Measures because that is one of the important concepts in Tableau.
• Get acquainted with the best practices of creating dashboards and visualizations and also DISCRETE and continuous views.
• Explain why you like Tableau or how it differs from other similar tools like QlikView or IBM Cognos. Your interest in BI tools will put you ahead in the competition.
• What are the scenarios where you’ll use Live connection or Data extract in Tableau?
• How dashboards are deployed on the Server.
• What was the maximum amount of data you have handled in Tableau? If you are learning Tableau, while practicing, check the size of your visualization or the TDE file.
• Create some visualization stories for sample work.
• How you will take requirements before creating a dashboarding application.
• What was your development methodology: WATERFALL or Agile?
• How much time it takes you to create a dashboard.

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.

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’.

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!

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.

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.

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.

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.

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

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.

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.