Topic: Store one db table in memory

Hi, I got finished Ruby on Rails project to optimize. And problem is that it reads over and over many times one small db table. I want to store that table in memory and filter data. What is the most efficient approach? I got this db query..

result= Project::Items.find(:all, :conditions => ['param1>= ? AND param2 <= ?)', condition1, condition2])

1.) I try to load full table to array of structure
all_items=Project::Items.all

     and then I filter result:
result = all_items.select {|p|  p[:param1] >= condition1 && p[:param2]<=condition2 }

     but result is wrong.. how can I filter that data correctly?

2.) How can I store array in session.

3.) There is memcache used in project. Can use it for storing such array.