create linked server to vertica
The driver in the connection string needs to be Vertica, not Vertica ODBC Driver 4.1.

EXEC dbo.sp_addlinkedserver 
    @server = N'VERTICA', 
    @srvproduct=N'', 
    -- SQL Server driver
    @provider=N'MSDASQL',
    -- Connection string
    @provstr=N'Driver=Vertica;
            Servername=ServerName;
            Port=5433;
            Database=DatabaseName;
            UserName=user;
            Password=pass'