ICML2026

The benefits of full data shuffle, now with optimal I/O cost: kk-wise independence and matrix transposition to the rescue

Peyman Afshani, Rezaul Chowdhury, Mayank Goswami, Jens Kristian R Schou, Francesco Silvestri, Mariafiore Tognon

Abstract

It is known that RandomShuffle, the without replacement version of Stochastic Gradient Descent (SGD), converges faster than with replacement SGD. However, RandomShuffle requires uniformly performing a random permutation of the input sequence, which is known to have high I/O complexity due to data movement across the memory hierarchy. In this paper, we propose a shuffling algorithm with a linear I/O complexity that generates almost-uniformly random permutations with rigorous mathematical guarantees. Specifically, we show that the shuffling algorithm can generate 22-wise independent permutations. Furthermore, we can extend to kk-wise independence with a small error in the probability distribution, if the fast memory has at least kk memory blocks. These results allow us to reach the same expected theoretical convergence as RandomShuffle while achieving optimal linear I/O cost.