Tableau Tutorial

The different layers of tableau server architecture are:

Data Layer:

The main component of Tableau Architecture is the data source that can be linked to it. Tableau can be linked to several data sources. These data sources can be on-site or remotely located. It can connect to a database, an excel file, and a web application at the same time. Tableau can connect data from heterogeneous environments. Data from various data sources can be blended. It can also create a relationship between different types of data sources.

Data Connectors:

Data Connectors provide an application for connecting external data sources to the Tableau Data Server. Tableau has an ODBC/SQL adapter built-in. This ODBC Connector will connect to any database without using its native connector. Tableau has the ability to pick both live data and extract data. Based on the use, it is simple to switch between extracted and live data.Tableau has the option of collecting data from external data sources. A local copy can be rendered in the form of an array extract format. It can extract millions of records with a single click in the Tableau data engine.Tableau can bind to real-time data simply by connecting to an external database. It uses the current database system infrastructure by submitting dynamic MDX (Multidimensional Expressions) and SQL statements. This function will connect to live data with Tableau instead of importing the data.

Related Article: Tableau Version History

Components of tableau server: The tableau server comprises three different components. They are:

1. Application server: The application server is used to provide authentication and authorizations. It manages the administration and authorization of online and mobile interfaces. Ensures protection by documenting each session id on the Tableau Server. The administrator will configure the default timeout of the session on the server.

2. VizQL server: The VizQL server is often used to translate applications from the data source to visual representations. When the customer order is submitted to the VizQL process, it transfers the request directly to the data source and retrieves the information in the form of an image. This image or visualisation is displayed to the user. Tableau server builds a visualisation cache to reduce the load time. The cache can be shared with several users who have permission to access the visualisation.

3. Data Server: Data servers can be used to manage and store data from external data sources. It's a centralized data warehouse. It usually deals with metadata, data protection, data storage, data link and user requirements. It stores the related data set information, such as metadata, measured fields, sets, classes, and parameters. The data source could retrieve information as well as intention to perform connections to external data sources.

Gateway:

The gateway channelizes user requests to the Tableau components. When the client submits a file, it is transferred to the external load balancing machine for storage. The gateway acts as a system distributor for different components. In case of lack of an external load balancing system, the gateway often acts as a load balancing device. For single server setup, all processes are handled by one primary server or gateway. For multiple server setups, one physical device acts as a main server while the other is used as a worker server. In the Tableau Server environment, only one computer can be used as a primary server.

Clients:

Tableau provides interactive dashboards for clients using zero-footprint HTML and JavaScript (AJAX) in a web browser, or natively through a smartphone app. No plug-ins or helper applications are required. Tableau Server supports the following types such as different web browsers, mobile apps, ipad app, android app and android browser, etc.

4. Tableau Environment and Work Space:

Here we are closely inspecting the working environment of the tabelus i.e  openings and closing of an application in the tableau.

Two steps to follow in order to work on the tableau desktop.

• First open the application on your computer, then select the teabalue workbook where you files related to tableau are stored here.
• After you're done with the work just look at the close icon at the top right corner of the application and then click it by saving your data.

Tableau workspace:

Tableau workspace comprises the following sets of things such as toolbar, menus, data windows, cards, legend and sheets, dashboards,and worksheets, etc. Worksheet hotels the sheaves that can be customized for effective use. In the shelves data fields are dragged so as to build views. Similarly the dashboards hold legends, filters and views.

The following image depicts all the components of the baleia workspace.

Data Window: 

• The data field resides in the data window on the left side of the workspace. 
• You can hide and view the Data window by selecting Window > Show Data Window. 
• You can also press the Minimize button at the top right corner of the Data window.

Status Bar:

• It is placed at the bottom of the workbook of the Tableau. 
• It displays explanations of the menu items as well as information on the current view.

ToolBar: 

• Tableau's Toolbar includes a command including Data Link, New layer, and Save. 
• It also includes analysis and navigation tools such as Type, Group and Highlight.

Cards and Shelves:

• The worksheets contain different types of cards that can be shown or hidden.
• They act as containers for shelves, legends, etc.
• They also are shown or hidden, rearranged around the worksheet.

You can see the placing of cards and shelves in the following image

5. Building views in tableau:

In order to create a view in Tableau, you can drag the fields from the Data window and drop the fields on the shelves that are part of all Tableau worksheets.

In order to build views automatically, one can take the advantage of the show me dialog box. By using the drag and drop field you can build the views, select the type that you want to create and click ok as shown in the below show me dialog box.

After creating the desired views and saving your data in the tableau workbooks.So as to save the data in the workbooks, you need to follow these steps.

• Select File > Save or press Ctrl + S on your keyboard.
• Browse to a file location to save the workbook.

And by default all your workbooks will be saved in the workbook directory of the tabelu repositories. You need to specify a filename for your workbook as well as the files type such as .twb or .twbx.

6. Tableau Data Source Connections:

There are several ways to connect data sources in tableau. In order to examine your tableau data first you need to connect your tableau to any of the data sources. The data source can be an excel worksheet, SQL server or an Oracle Data warehouse. After linking, data fields are displayed in the Data window on the left side of the workbook.Tableau supports various array data sources, such as multi-dimensional databases, SQL databases, etc.

Related Article: Tableau Parameters

Now we are going to learn how to connect to the tableau data source and connect to a custom SQL  query.

Follow these steps to connect to the tableau data source. They are

• First connect tableau to the data source so as to build views of the data.
• Next you can easily connect to any supported data sources with the help of a dialog box.
• Select Data > Connect Data or click Ctrl+D on your keyboard. You can also choose the option Connect to Data on the start page.

In order to connect to the data page, choose the type of data you want to connect to and you can also select a saved data link (TDS files) to open a Tableau Server Data Source.

Opens a specific Data Source dialogue that helps you to complete the connection process. To connect to array data in a particular way, you need to import the data from a workbook. There are several worksheets in the workbook, each of which can be added to a separate table of various data sources. To import a connection from a workbook, press the Import from Workbook button at the bottom of the Select Saved Connection tab in the Data Connection dialogue box.

If the connection is formed, the array data sources fields are displayed in the Data window on the left side of the workbook.

Connecting tableau to a custom SQl query:

Relational data sources that can be connected to a particular query rather than to the entire data source. This can be useful if you know the details you need and understand how to write SQL queries correctly.

• Pick Custom SQL from the Link dialogue box. 
• Type or paste the question in the text box. The button in the upper right corner of the text box opens a wider edit window for more complicated queries.

Only the required fields are displayed in the Tableau Data window when the connection is terminated. If your SQL query indicates duplicate columns, you can get errors when you try to use one of the columns in the Tableau. This will also happen, even though the question is valid.

Next we are going to learn how to export database connection in tableau.

7. Exporting Database Connection in Tableau:

After connecting to the data source, we now have to export the link data as an alternative route that allows fast connections while opening the connection dialogue box. If you frequently connect to a similar data source many times, or if you have attached custom fields to the Data window, such as measured fields, binned fields, or joined tables. Use the alternative route or shortcut for the following connections to that source so that you do not have to re-establish custom fields.

8. Data Blending and joining tables in tableau

When the data is blended from multiple sources on a single worksheet, it is referred to as data blending. The information is connected to the common dimensions. 

Does not build row-level joins . So this is not a way to add new dimensions or rows to your results. It can be used when you have similar data in a variety of data sources that you want to analyse together in a single view. To combine a data blending array, you should first add one of the common dimensions to the view from the primary data source.

In order to blend data on the worksheet needs the following steps.

• First connect to the sample, i.e the excel spreadsheet and then build views by specifying the categories.
• Select the data and connect to the data and then connect it to the spreadsheet.
• Just drag the spreadsheet to know or measure the details of the shelves.
• Just do right click on the spreadsheet and add the reference line.
• A reference dialog box will be opened, add the reference line and then click ok.
• Now the worksheet is pulling the data from the secondary data sources so as to compare both the actual and forecast parameters.

Tableau joins:

Multiple relational data sources consist of a set of tables which are related to specific fields. For example, a table to enter data sources for an organisation which include an employee table containing the employee's first name, last name, telephone number, etc.

If you first connect to the Data Source array using the Connection dialogue, you can connect to multiple tables. Here you can add tables, enter tables, and change field aliases if you are likely to have named fields in each table. If you've already linked to the data source, you can add the tables as well. This section discusses how to link to a number of tables and how to add tables to the Data window.

Connecting to multiple tables:

Follow the below mentioned step to connect to the multiple tables.

• You need to select the table and then go for the multiple tables option as shown below.

• Then click add a new table button that is displayed at the bottom of the screen, as shown in the above image.

• Next select the table to add the data window in the add table dialog box.

There is a catalogue of fields with their aliases at the bottom of the Add Table dialogue box. Double click the alias field to adjust how the field will be represented in the Data window. This is useful when you have copied field names around tables, or when your field names are not very simple. 

Connect to this by clicking the Join tab.Tableau will automatically create a connection for you based on the formation of your data. Click the Joins tab to check the Join Clause to make sure it is the way you want to connect the tables. 

You can delete useless Join Clauses by selecting them in the Join Clauses catalogue and clicking Delete.By selecting a field from the original table, a field from the added table, and an operator, you can add one or more joining clauses to the attached panel. After that, press the Add button to add it to the Join Clause list. 

According to the earlier discussion data source, two tables have order information and user information, so we can enter both tables based on the region area. Select Region in both field lists, select an equal sign as an operator, and then press Add.

You can select Inner, Left, or Right join from the Join Type drop-down list.

Note, you can’t nest Inner joins inside Left or Right joins. Because these joins will cause a join expression not supported error.

When finished, click OK.

In connection dialog box tables are listed with the foreign keys.

End the connection by giving it a name and clicking OK.

When we add Tableau join tables, Group by table command is used when the data window is automatically organized. You can turn off this feature or change how the Data window is sorted using the Data window menu.

Adding and editing tables to the data window:

In order to add tables to the data window, you need to focus on the following points.

• First select the data source on the data menu and then select the edit tables.
• In the table dialog box, click add new table.
• In the Add Tables dialog box, select a table to add. Complete the dialog box by defining at least one tableau data joins clause and optionally changing field aliases.
• When finished, click OK and then OK again to close the dialog boxes.
• When you connect to several tables you are necessarily connecting to a denormalized view of the data source. This means that all queries are run against all tables and it is possible for some measures to be overcounted.

Editing tables:

By using the tables command you can easily edit the tableau data join tables. In order to edit just select the data source on the data menu and then select the edit tables. In the tables dialog box, just select the tables you want to modify and click on the edit. You can change the table and field aliases as well as add and delete fields from the Data window in the following dialogue box. Choose the Join tab to edit the attached clauses. When done, press OK twice to close the Tables dialogue box.

9. Extracting data in Tableau:

To boost performance and data to allow more advanced functionality and to analyse offline, you can use table data extracts which are stored subsets of the data source. You may make an extract of Tableau data by specifying philtres and limits that include the data you want in the extract of the collection.

After building a Tableau data extract, you can reload the data from the original data source. You can either update the data, replace all the contents of the table extract data, or you can add a table extract that only adds rows that have been new since the last refresh.

Tableau data extracts can helps in:

• Improving the performance.
• Creating tableau extracts
• Adding rows form a file
• Optimizing tableau extracts
• Refreshing tableau data extracts
• Provide access to offline data.

10. Creating tableau dashboards:

Follow these simple steps to create dashboards in the tableau. They are;

• Just right click on the tab list and select the new dashboard form the context menu.
• Click the New Dashboard tab at the bottom of the workspace, or select Dashboard,from the drop-down menu. 
• A blank dashboard will appear with the Data window replaced by four sections: a list of existing worksheets in the workbook, a set of additional dashboard elements in the layout section containing the arrangement of items added to the dashboard, and a section for customization of the dashboard element sizes.

11. Tableau Vs BI:

Tableau is a powerful and fastest-growing data visualisation tool used in the business intelligence industry. It allows you to simplify raw data into a very easily understandable format. Power BI is a Business Intelligence and Data Visualization tool that helps you convert data from different data sources to interactive dashboards and BI reports. It also offers a range of device connectors and facilities.

Conclusion:

Tableau is very easy, fast, to create data visualizations.It lets you combine form and clean data for study. It lets you manage a large amount of info. Using scripting languages such as Python, R to avoid performance for complex table calculations. Allows users to use Tableau Desktop to build reports, dashboards, etc.