The belief that the state file should be stored in /dev/shm/, and that it was best to either rely on swapping or having enough RAM to hold the entire state file was a large part of this misconception.
So essentially the suggestion is, only during the initial indexing the files needs to be read quickly and from that point onwards only the last blocks will need to be in the RAM for faster I/O ?
In otherwords, once the reindexing is over, which is CPU driven and IO driven, the "tail end of the blockchain" is what that gets I/O and rest need not be in memory.
If this is the case, we need to carefully pageout the older parts of the blockchain from the memory and only the new (tail end) needs to be in memory.
Does this make sense ?