I have not connected to the Snappy DB as a data source with Tableau Desktop. Though I would be more than happy to help research some potential solutions. First off, I am not certain on how the connection to the Snappy DB is being made. But I would review the possible options below and let us know in your reply whether it is a WDC, ODBC or another type of data source connection. The reason I ask is there are different locations for receiving help in the Tableau Community depending on the data source and I want to make sure we have your post in the best location!
Though I would be more than happy to provide some information on connecting to data sources that are not currently named connectors and listed on the Tableau Desktop technical specifications page. One of the first methods is to mirror the data into a supported data source.
If available for the database Tableau has an ODBC connector can be used to most data sources that have an ODBC driver. I am including several resources for the ODBC connection below. There can sometimes be limitations when using the ODBC connection versus a named connection that is listed in the explicitly on the data source page.
Also, if the data is available over HTTP, the connection to data source can be made with the WDC(Web Data Connector). I have included several resources for using the Tableau WDC below. The first link is to the Tableau Online Help on the WDC feature. Additionally, I included links to the specific section in the community and the Tableau GitHub section on the WDC.
Another option is to use the Tableau SDK, to create a .tde file of the data set to then be used in the Tableau Desktop program. Additional resources and information can be found below.
I hope these resources help!