Java large datastructure for storing a matrix

Question

I need to store a 2d matrix containing zip codes and the distance in km between each one of them. My client has an application that calculates the distances which are then s

Answer 1

The above suggestions regarding heap size will be helpful. However, I am not sure if you gave an accurate description of the size of your matrix.

Suppose you have 4 locations. Then you need to assess the distances between A->B, A->C, A->D, B->C, B->D, C->D. This suggests six entries in your HashMap (4 choose 2).

That would lead me to believe the actual optimal size of your HashMap is (952 choose 2)=452,676; NOT 952x952=906,304.

This is all assuming, of course, that you only store one-way relationships (i.e. from A->B, but not from B->A, since that is redundant), which I would recommend since you are already experiencing problems with memory space.

Edit: Should have said that the size of your matrix is not optimal, rather than saying the description was not accurate.