How should I deal with a very large array in Java?

Question

I have an algorithm which currently allocates a very large array of doubles, which it updates and searches frequently. The size of the array is N^2/2, where N is the number of

Answer 1

I've had generally good experiences with Java's MappedByteBuffers, and encourage you to have a deeper look at it. It very well may allow you to not deal with the -Xmx changes again. Be aware that if you need more than 2-4GB of addressable space then a 64-bit CPU, OS and JVM are required.

To get beyond the Integer.MAX_VALUE indices issue you could write a paging algorithm, as I have done here in a related answer to Binary search in a sorted (memory-mapped ?) file in Java.