Access SQL Analysis Services Data as OData Feeds in Tableau

The CData API Server, when paired with the ADO.NET Provider for SQL Analysis Services (or any of 200+ other ADO.NET Providers), provides SQL Analysis Services data as OData Web services. This article will explain how to use the API Server to provide the underlying connectivity to SQL Analysis Services data in Tableau's business intelligence tool.

Set Up the API Server

Follow the steps below to begin producing secure SQL Analysis Services OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to SQL Analysis Services

After you deploy the API Server and the ADO.NET Provider for SQL Analysis Services, provide authentication values and other connection properties needed to connect to SQL Analysis Services by clicking Settings -> Connections and adding a new connection in the API Server administration console.

To connect, provide authentication and set the Url property to a valid SQL Server Analysis Services endpoint. You can connect to SQL Server Analysis Services instances hosted over HTTP with XMLA access. See the Microsoft documentation to configure HTTP access to SQL Server Analysis Services.

To secure connections and authenticate, set the corresponding connection properties, below. The data provider supports the major authentication schemes, including HTTP and Windows, as well as SSL/TLS.

• HTTP Authentication

  Set AuthScheme to "Basic" or "Digest" and set User and Password. Specify other authentication values in CustomHeaders.

• Windows (NTLM)

  Set the Windows User and Password and set AuthScheme to "NTLM".

• Kerberos and Kerberos Delegation

  To authenticate with Kerberos, set AuthScheme to NEGOTIATE. To use Kerberos delegation, set AuthScheme to KERBEROSDELEGATION. If needed, provide the User, Password, and KerberosSPN. By default, the data provider attempts to communicate with the SPN at the specified Url.

• SSL/TLS:

  By default, the data provider attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store. To specify another certificate, see the SSLServerCert property for the available formats.

You can then access any cube as a relational table: When you connect the data provider retrieves SSAS metadata and dynamically updates the table schemas. Instead of retrieving metadata every connection, you can set the CacheLocation property to automatically cache to a simple file-based store.

See the Getting Started section of the CData documentation, under Retrieving Analysis Services Data, to execute SQL-92 queries to the cubes.

When you configure the connection, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.

You can then choose the SQL Analysis Services entities you want to allow the API Server to access by clicking Settings -> Resources.

Additionally, click Settings -> Server and set the Default Format to XML (Atom) for compatibility with Tableau.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. Access can also be restricted based on IP address; by default only connections to the local machine are allowed. You can authenticate as well as encrypt connections with SSL.

Create Real-Time SQL Analysis Services Data Visualizations

Follow the steps below to create data visualizations based on the remote SQL Analysis Services data:

1. In Tableau, select 'Connect to data'. In the 'On a server' section, click OData.

   

2. In the resulting wizard, enter the URL of the OData endpoint for the API Server. Append the name of the table you want to access to the OData entry URL. For example:

   https://your-server/api.rsc/Adventure_Works
3. Select the 'Use a Username and Password' option and enter the username and password of a user who has access to the API Server.

4. Tableau uses the table metadata exposed by the API Server to detect dimension and measure columns.

   

5. To view the SQL Analysis Services data, right-click under the table name in the Data section of the dashboard and select the View Data option. The SQL Analysis Services data will appear in Tableau.