drop table but file still exists

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

On Fri, 2009-05-15 at 09:09 +0200, Luca Ferrari wrote:

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?

To avoid various problems the files are removed after the next
checkpoint.

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support