just have a look on youtube, there are a number of learners' videos available. Also there are a number of blogs and
other resources on this site that should answer most of your questions.
- "In memory" just means that the entire program, as well as the working data, is stored in working memory, which makes the whole thing extremely fast.
If you have worked as a programmer, there's no need to worry about prerequisites to using QlikView. It's pretty easy to get into.