Building large Linear Program
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I want to build an LP whose parameters are given by, between 5 and 10, 25,000,000 to 50,000,000 row .csv files (approx 500mb to 1Gb each). 

My model is currently coded in AMPL, and reads in the parameter values directly from the .csv files. The Windows XP with 1 Gb RAM I am using runs out of memory trying to build a model based on data from only one 500mb .csv


My question:
Is there a way to manage my data so that I can build the LP using less memory?

I appreciate all feedback from anyone with experience building massive LP.