Thanks Vaughan, interesting article.
It depends on how record pointers are represented internally in FM (which is able to address 64 quadrillion records per table; I assume this is US short notation, so 64*10^15 records = ca. 2^55).
If, however, the sort algorithm of FM uses 32bit pointers, then we may sooner or later run into a problem. E.g. I have
one 40 GB database with about 306 million records (still far away from the 2^31 -1 = 2.15 billion record limit); for certain export operations, this DB needs to be sorted.