can i clear without the scwcd knowledge Yes, you can clear bcd without wcd, I have done so but I did it because I was waiting for HF
servlets to be released. Unless you have work experience in EJBs or there is some other obligatory reason to clear bcd earlier than wcd, I would recommend you SCWCD before SCBCD.
EJB's have more abastract ideas than Servlets and
JSP.
Hope this helps.