Nested loops join algorithm – additional available page buffers

The basic version of nested llops join algorithm only uses two main memory page buffers for loading the pages.

But if additional page buffers are available the I/O cost can be reduced.

Should I chose to use the additional available page buffers to hold more pages of the relation considered by the outer loop or the inner loop?

And why?

I apologies if this is the wrong place to post this question Thanks in advance,