I think the -B flag is in fact the cache buffer. Here is an
article by Bruce Momjian which is where I got that.
Anyway, there don't seem to be anywhere near as many knobs to turn on postgresql as on oracle but sadly even less guidance about how
to turn those knobs that there is on oracle. Roberto
also pointed me at this tuning article but I am not so sure about it since one
thing he does is set fsync=false with no real discussion
of the consequences.
