First you want to make sure that the Pentaho version is the 6.1 version or above.
Next, these steps will help you create the JDBC connection to Snowflake through Pentaho:
1. You will need to download the Snowflake JDBC driver to the workstation while at the same time running Pentaho
2. Then you will copy Snowflake_jdcb.jar to the Pentaho folder:
-On Windows this will be: C:\ProgramFiles\pentaho\design-tools\data-integration\lib
-On Mac OS this will be: …/pentaho/design-tools/data-integration/lib
3. Lastly, you will configure a Generic Database connection within Pentaho through:
Driver Class Name: net.snowflake.client.jdbc.SnowflakeDriver