I cannot say in very detail. I would recommend using the specific connectors for Big Data systems. The configuration should look mostly the same. Otherwise you might just give it a try.
Big data systems have some special characteristics that would differ from ‘normal’ databases. If you just use open SQL (HQL) syntax it might not make that much of a difference. Otherwise with the Hive and Impala connectors you give other KNIME DB nodes a chance to know that they are dealing with a Big Data system.