Re: fallocate / posix_fallocate for new WAL file creation (etc...)

On 5/28/13 11:36 AM, Greg Smith wrote:
> Outside of the run for performance testing, I think it would be good at
> this point to validate that there is really a 16MB file full of zeroes
> resulting from these operations.  I am not really concerned that
> posix_fallocate might be slower in some cases; that seems unlikely.  I
> am concerned that it might result in a file that isn't structurally the
> same as the 16MB of zero writes implementation used now.

I see nothing in the posix_fallocate() man pages that says that the
allocated space is filled with any kind of data or zeroes.  It will
likely be garbage data, but that should be fine for a new WAL file.