Sunday 3 April 2016

Tableau and HANA


Tableau is an easy to use visualization tool that allows you to connect to various types of data sources, visualize and create interactive dashboards and story points.

Connecting HANA and Tableau

After reading Ronald's blog, I thought connecting Tableau to HANA is very easy but when I tried to connect Tableau to HANA using Native Connector, I got the below error

Tableau and HANA

I had both HANA Client and HANA Studio installed in the System.
Then I tried to connect Tableau to HANA using Generic ODBC Connection and was able to connect to HANA as shown below:

Tableau and HANA

Then I tried to find the reason as to why Tableau was not able to connect to HANA via its native connector
The reason behind Tableau not getting connected was that my HANA ODBC Driver name was HDBODBC32_003.

I tried uninstalling HANA Client and installing it again - but the new ODBC driver also got installed with name HDBODBC32_003. The reason being that there was another ODBC driver entry with name HDBODBC32_002 and it was corrupted.

So I had to delete the HDBODBC32_002  entry from Windows registry

Tableau and HANA

Once I deleted the HDBODBC32_002 entry from registry and uninstalled and installed HANA Client again, ODBC Driver got installed as HDBODBC32.
After that I was able to connect to HANA using Tableau Native Connector.
To connect to HANA, just enter Server Name and Username and Password as shown below:

Tableau and HANA

Then select the Schema and then the table or view to which you want to connect.
If you want, you can even write the custom SQL Query to get the data from HANA.

Tableau and HANA

Now drag your View/table to get the data from HANA.
If you are using Tableau 8.2 and your View has input parameters or variables then you will get a popup asking to enter values for input parameters or variables.
Note: If you are using Tableau Version below 8.2, the Input Parameters are not supported.

Tableau and HANA

Then choose whether you want to connect to HANA using a Live connection or want to create a Data Extract and then preview the data.

Tableau and HANA

After this, click on Go to Worksheet and create the Visualizations you want.

Tableau and HANA

Then you can combine different visualizations into one dashboard or combine dashboards and worksheets to create a Story Point.

Once the dashboard is created there are multiple ways to share it. You can publish the Dashboard to Tableau Server or Tableau Online.

There is also a free tool provided by Tableau called as Tableau Reader. It can be used to view and interact with Tableau Packaged Workbooks. But its drawback is that it can't connect to Live Data Source and if you try to open a Workbook that has Live Data Source, it throws the below error.

Tableau and HANA

To resolve this error, instead of creating a Live Connection to Database you will need to create a data extract that will save in your local Desktop.

Now lets discuss some advantages and limitations of Tableau

Advantages of Tableau
  • Shows beautiful data visualizations with lot of charts
  • Has very interactive analysis with simple drag and drop functionality
  • Very easy to customize the layout and information displayed
  • The visualizations can be integrated into a dashboard or story point and linked to each other
  • Can connect to HANA table, HANA View and also supports Custom SQL
  • Can publish the dashboards to a PDF
  • Has good training material for self-learning

Limitations of Tableau 
  • HANA Input parameters not available for end user, they just filter out the data at Data Source level, so if we want to create interactive dashboard then we need to create additional parameters in Tableau on top of the data that we are getting from HANA View
  • High Cost for a Broad Adoption as Dashboards created in Tableau Desktop with Live connection to database can be opened only in Tableau Desktop, Tableau Server or Tableau Online and it is very costly
  • Only 32 bit Support for HANA
  • Tableau Reader cannot be used to open dashboards which have Live Connection to HANA
  • Can not be used for huge amount of data 

As Tableau has started supporting Input Parameters for Data Source in HANA, I hope that later we get an option to expose these parameters directly to end users and then it will become a great platform for even reporting purposes using the full processing power of HANA and great visualization capability of Tableau.


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