How to scan through really huge files on disk?

Question

Considering a really huge file(maybe more than 4GB) on disk,I want to scan through this file and calculate the times of a specific binary pattern occurs.

My thought

Answer 1

Tim Bray (and his readers) explored this in depth in his Wide Finder Project and Wide Finder 2. Benchmark results show that multithreaded implementations can outperform a single-threaded solution on a massive Sun multicore server. On usual PC hardware, multithreading won't gain you that much, if at all.