Avatto>>DATA SCIENTIST>>SHORT QUESTIONS>>Tableau Interview Questions
Tableau is a Business Intelligence Application. Tableau is used to create visualizations and interpret data. Tableau follows the basic principles of BI i.e. extracting raw data, transforming it, and presenting the data visually so that Business users can make informed decisions.
Tableau Architecture follows as below

Explain Tableau Architecture?

1)Data.Tableau can connect to any format of source data.
2)Data Connectors. Tableau provides over 40 optimized data connectors. To various data sources such as MS Excel, MS SQL Server, Google Big Query, Amazon RedShift, Oracle, and others.
It also provides a generic ODBC connector for systems without a native connector.
Data can be used in-memory or live.

3)Components. The following components handle the server operations
a)Application server. Application Server processes (wgserver.exe) handle content browsing, Server- Administration, and authentication to Tableau server web and mobile interfaces.
b)VizQL Server. When a user/client requests a visualization, it sends a request to the VizQL process (Vizqlserver.exe). The VizQL process in turn sends queries to the data source, returning a result set in the form of images. 
c)Data Server. It facilitates the management of data sources on the server.

4)Gateway/Load balancer. Gateway directs requests to other components.
5)View. Users can view Tableau dashboards thru Tableau desktop or via zero-footprint HTML 5 in a web or mobile browser.
The basic components of Tableau are Tableau Desktop, Tableau Reader, and Tableau Server.

-The developer uses Tableau desktop to create visualizations, dashboards, and stories.

-Dashboards can be deployed on the Tableau Server. Users can access dashboards stored on the server through the server URL. Tableau desktop can use data as a “Live” connection or as an “Extract” (TDE).

-Data connection/s used in developing dashboards is reusable. It can be published to the server. Data load schedules can be created to meet user requirements.

-Tableau desktop design file is called a “Workbook”. It has an extension .twb.

-Tableau workbooks can also be packaged with data. This packaged workbook is a zip file with extension .twbx.

-In the absence of the server, Tableau design files can be viewed by using Tableau Reader. Tableau reader is also a free download and can open twbx files.
Tableau using powerful visualization helps in understanding the data.

Tableau dashboards are interactive and display the whole picture of the data. All the data is present, data analysis across different time periods and dimensions is faster.

Datasource used in the dashboard design can be shared with other developers and users, this helps in maintaining the single version of the truth.

Development is faster as compared to other applications. Tableau provides easy to use functionalities to create data hierarchy, calculated fields, filters, parameters, Sets, and Bins.

Development is not IT-centric. It gives power to business users. Users can design their own dashboards.

Creating worksheets, dashboards, and stories are easy.

Based on the data, Tableau’s “Show Me” feature suggests users the best visualization type to use. This helps novice users in creating meaningful charts and tables.

Tableau can handle huge amounts of data. Connection to the data can be live or to an extract.

For a quick review, workbooks can be emailed as packaged workbooks with data.

Publishing to the server and applying security is easy.
Tableau development environment works as follows,

-Tableau desktop is used for creating visualizations such as charts, tables, and Maps.

-Users can connect to any data source. If multiple tables are used, then these tables can be joined. Data Sources can be named and shared.

-When the data source is created, depending on the data type, Tableau automatically segregates data into measures and dimensions. Data elements can be transformed.

-These data elements are used to create charts, tables, and Maps by simple drag-and-drop of data elements into the development area.

-One visualization is created per “worksheet”. Multiple worksheets make one “dashboard”.

-If the user needs a “story”, worksheets and dashboards can be used to create a story.

- Worksheet, Dashboards, and Story is created by clicking on the icons at the bottom of the screen How does Tableau development environment works?
or by using the menu optionsHow Tableau development environment works?


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