Issue while creating variables

[Nageswara Reddy Kondreddy (Product Architecture)]

Hi Team

I am creating a MILP model using Google OR Tools and failing while creating variables. 

x = {(k, s): solver.IntVar(0, 99999, f"x_{k}_{s}") for k in K for s in S}

where

len(K)
18304
len(S)
80000

That means 1.46432 billion of x variables has to create, could you please suggest how I can handle/fix this issue?

[Laurent Perron]

do not use a naive model

Laurent Perron | Operations Research | lpe...@google.com | (33) 1 42 68 53 00

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[Nageswara Reddy Kondreddy (Product Architecture)]

Laurent, then how to use

[Laurent Perron]

It is not a question of usage, it is a question of model.

Imagine a variable takes 100 bytes (which is too low), you would need 146GB of memory just to store the variables. And I am not talking of constraints.

So you need to create a better/smaller model.

Laurent Perron | Operations Research | lpe...@google.com | (33) 1 42 68 53 00

To view this discussion visit https://groups.google.com/d/msgid/or-tools-discuss/8c09a1f4-8537-4d3a-855c-b1d96e617c53n%40googlegroups.com.