[gvinciguerra]

From a Big-Oh point of view, the answer is a big yes. No matter the memory technology or the disk page size, be it 256B or 16KB, the PGM-index can scale as B-trees or even better (see my comment here https://news.ycombinator.com/item?id=25901889).

[thesz]

Can you provide us with (preferably drop-in) replacement of LMDB as a proof?

Because your big-O looks like big-O of cache-oblivious algorithm and I saw no proof of that.