Hi, I've read on railsexpress that one of the bottleneck of rails performances is building ActiveRecord object from big complex querys. So I wanted to use the select statement to ease it up a bit, but I came to realize that :select isn't used when :include is in ex : Book.find(:all, :select=>'books.title') works ex : Book.find(:all, :select=>'books.title', :include=>[:author]) gives me every single column.
Is their a (simple) workaround, am i doing anything wrong ?
thanx for your help
just did a google and got this: http://dev.rubyonrails.org/ticket/5371
Seems it's a bug. I've been working with rails for a year now, but i'm
an amateur programmer and digging in to core is out my scope.
Hope somebody gets on that one 
I've run into this as well.
If you think about what's happening with the SQL command when querying with and :include, it makes sense.
If you just selected "books.title", then it wouldn't get any of the author columns and couldn't populate the author object. What you probably want in the end is something like "books.title, authors.name".
In the long run, I don't think selecting all the columns is a very large performance hit, I'd test the trade off between eager loading (:include) and limiting you select columns (:select). I suspect that the eager loading will give you better results.
.adam