Hi,
I am new to Business objects.I am learning the subject.Can any one please clarify my doubts.
when to use alias?
->when to use context
->how do you design an oltp system?
->how to increase performance of oltp system?
-Rosy
rosy123 (BOB member since 2010-06-07)
There is already a long topic (a “sticky” at the top of this forum) related to aliases, contexts, and loops. There are a number of blog posts (from myself and others) that can easily be found via an Internet search on the same topic.
As for your other questions, they are equally as broad and probably have plenty of information available. There are also training courses for universe design that give you a good foundation and allow you to ask more specific questions. But I mentioned that to you already. 
BOB isn’t a substitute for a training course, or even having a good consultant come on site for a few days of mentoring.
Dave Rathbun 
(BOB member since 2002-06-06)