Moving from .Net/Java to Rails

Hello,

First let me thank you for your willingness to aid me in my efforts to
use Ruby (on Rails) in our company to replace existing and fureture
planned development in .Net and Java.

I have been working on an appication for a couple of years that has been
written in .Net using C#, but due to a short list of reasons we are
seriously thinking about re-writing our web application in Rails -- or
at least I am.

While we are evaluating our various options another well experienced
Java developer is pushing the use of Spring and Hybernate and I am
advocating the use of Rails. Two out of the three engineers -- including
myself -- have experience with rails but have not built large web
applications as of yet and need some more information about how we will
approach a couple of our unique problems with Ruby.

So here is one of the big issues that we are facing and I wondered if
any experts out there could give me some advice on ways we can handle it
and other more computation intensive operations using the rails stack.

Ruby really isn't the best language for computation intensive work. Of
course you could still do the front end in rails, just hand off the
heavy lifting to a Java powered web service.

We have 2.7 million geographic destinations in our application that are
currently stored in a memory cache and are used throughout our
application heavily. This is used for finding nearby destinations,
getting destination heigharchy information, etc. We also have a ajax
auto complete feature that does a prefix match on the cached
destinations.

Rolling your own GIS system? Any reason why you can't use e.g. PostGIS?

Isak