Redmine

I'm a developer with experience in web development under both .NET and C++ (the latter is a bit strange I know, but still) and one thing Redmine impresses me with is how responsive it is.

I haven't made any actual tests so far, so my impression is completely subjective.

Also, my redmine runs with sqllite and since I don't know what database this site runs on, I can't say for sure how other backends feel.

I also have an understand of why and how web applications can be slow in general, so I'd have a basis to do research.

Still, I thought it's worth asking around here first. I'm looking for information regarding the following questions:

1. Is redmine unusually responsive for a web application or am I mistaken in my subjective feeling?
2. If not, is redmine particularly responsive for a ruby-on-rails application or is this a general result of something the framework provides?
3. If so, what does the framework do to make that happen in contrast to other technologies? I know that rails usually runs in a module rather than over cgi or fcgi, which makes sense perforamce-wise. The obvious other candidates for optimization would be caching to avoid database accesses. Can anybody point to information about any such rail's caching facilities if applicable? Does anybody knows how often the database is accessed when I do redmine requests?

As I said, I'm capable of profiling my own apps and I don't need any generic advice on that topic. I'm only specifically interested in anything that might apply to redmine or rails in particular that could be considered unusual and is worth mentioning.

I also want to apologize in case I might appear lazy. I know I can investigate such questions myself, but it's possible that there is already a nice read somewhere and someone knows a good link - so that's why I try it this way first.