Re: Block at a time ...

Greg Stark <gsstark@mit.edu> writes:
> I think we need posix_fallocate().

The problem with posix_fallocate (other than questionable portability)
is that it doesn't appear to guarantee anything at all about what is in
the space it allocates.  Worst case, we might find valid-looking
Postgres data there (eg, because a block was recycled from some recently
dropped table).  If we have to write something anyway to zero the space,
what's the point?

            regards, tom lane