Luca Ferrari <fluca1978@infinito.it> writes:
> I'm just curious to know why after a drop table the disk file is emptied but
> still existent. What is the reason why the file is not deleted immediately?
It's protecting against some obscure race condition involving
reassignment of the relfilenode number to a new table. I forget the
details but you could troll the archives for it if you really care
--- I think we put that in about two or so years ago.
regards, tom lane