while it's unlikely you'd allocate a memory array[2^30] on a 32-bit machine, I also use binary search on mmap'd files. Specifically, text files. Binary search

while it's unlikely you'd allocate a memory array[2^30] on a 32-bit machine, I also use binary search on mmap'd files. Specifically, text files. Binary search doesn't need the exact midpoint, just somewhere nearby, so I pick the midpoint and look around for line boundaries. On normal sorted text files, this works fairly well. I was able to search a list of a billion IP addresses while touching only a few pages. https://gitlab.com/mac3n/ksip https://gitlab.com/mac3n/ksip