Spark -Teradata connection Issues

Exception: 

Caused by: java.lang.NullPointerException

        at com.teradata.tdgss.jtdgss.TdgssConfigApi.GetMechanisms(Unknown Source)

        at com.teradata.tdgss.jtdgss.TdgssManager.<init>(Unknown Source)

        at com.teradata.tdgss.jtdgss.TdgssManager.<clinit>(Unknown Source)

Brief:

tdgssconfig.jar can't be found on the classpath. Please add same on classpath.

Exception: 

java.sql.SQLException: [Teradata Database] [TeraJDBC 15.10.00.33] [Error 3707] [SQLState 42000] Syntax error, expected something like a name or a Unicode delimited identifier or an 'UDFCALLNAME' keyword or '(' between the 'FROM' keyword and the 'SELECT' keyword.

Brief:

Normally Spark JDBC expects DBTable property to be a Table Name. So, internally it prepends "select * from" to Table Name. Like 

select * from <Table Name>

But, If we specify SQL instead of  Table Name then internally SQL will become something like:

select * from select ... ;

Above makes it syntactically incorrect leading to above error. Solution is to provide subquery with an alias such that it will make internal SQL syntactically correct.

select * from (select ...) alias