Good questions. I updated the initial post with the following information:

1. I have a large equation that I need to manipulate. In a previous post folks tried using a variety of hashes, arrays, strings, etc to handle the manipulation. All attempts ended with Out of Memory. Hence I need to externalize parts of the equation into files or some other non RAM memory store.

2. Tried on Linux (RedHat), Solaris, Windows XP on 5 machines ranging from 4 core to 8 core with 4-16 gigs of memory.

3. Yes 5.8 and 5.10

4. I've tried a variety of PERL based constructs to store and manipulate the symbolic equation - hash, arrays, strings. I've tried a couple different versions of PERL (due to different versions being on different systems)

5. Thanks! Is there an equivallent for windows?

Overall I am looking for an approach which I thought would be independent of these tactical factors. That is, if you have a program that runs out of RAM and given PERL is relatively OS independent, is there a common preferred way to manage this situation. I was thinking databases were the way to go but I am not sure.